// SPDX-License-Identifier: GPL-2.0-only /* * linux/fs/nfs/write.c * * Write file data over NFS. * * Copyright (C) 1996, 1997, Olaf Kirch */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "delegation.h" #include "internal.h" #include "iostat.h" #include "nfs4_fs.h" #include "fscache.h" #include "pnfs.h" #include "nfstrace.h" #define NFSDBG_FACILITY NFSDBG_PAGECACHE #define MIN_POOL_WRITE (32) #define MIN_POOL_COMMIT (4) struct nfs_io_completion { void (*complete)(void *data); void *data; struct kref refcount; }; /* * Local function declarations */ static void nfs_redirty_request(struct nfs_page *req); static const struct rpc_call_ops nfs_commit_ops; static const struct nfs_pgio_completion_ops nfs_async_write_completion_ops; static const struct nfs_commit_completion_ops nfs_commit_completion_ops; static const struct nfs_rw_ops nfs_rw_write_ops; static void nfs_inode_remove_request(struct nfs_page *req); static void nfs_clear_request_commit(struct nfs_commit_info *cinfo, struct nfs_page *req); static void nfs_init_cinfo_from_inode(struct nfs_commit_info *cinfo, struct inode *inode); static struct kmem_cache *nfs_wdata_cachep; static mempool_t *nfs_wdata_mempool; static struct kmem_cache *nfs_cdata_cachep; static mempool_t *nfs_commit_mempool; struct nfs_commit_data *nfs_commitdata_alloc(void) { struct nfs_commit_data *p; p = kmem_cache_zalloc(nfs_cdata_cachep, nfs_io_gfp_mask()); if (!p) { p = mempool_alloc(nfs_commit_mempool, GFP_NOWAIT); if (!p) return NULL; memset(p, 0, sizeof(*p)); } INIT_LIST_HEAD(&p->pages); return p; } EXPORT_SYMBOL_GPL(nfs_commitdata_alloc); void nfs_commit_free(struct nfs_commit_data *p) { mempool_free(p, nfs_commit_mempool); } EXPORT_SYMBOL_GPL(nfs_commit_free); static struct nfs_pgio_header *nfs_writehdr_alloc(void) { struct nfs_pgio_header *p; p = kmem_cache_zalloc(nfs_wdata_cachep, nfs_io_gfp_mask()); if (!p) { p = mempool_alloc(nfs_wdata_mempool, GFP_NOWAIT); if (!p) return NULL; memset(p, 0, sizeof(*p)); } p->rw_mode = FMODE_WRITE; return p; } static void nfs_writehdr_free(struct nfs_pgio_header *hdr) { mempool_free(hdr, nfs_wdata_mempool); } static struct nfs_io_completion *nfs_io_completion_alloc(gfp_t gfp_flags) { return kmalloc(sizeof(struct nfs_io_completion), gfp_flags); } static void nfs_io_completion_init(struct nfs_io_completion *ioc, void (*complete)(void *), void *data) { ioc->complete = complete; ioc->data = data; kref_init(&ioc->refcount); } static void nfs_io_completion_release(struct kref *kref) { struct nfs_io_completion *ioc = container_of(kref, struct nfs_io_completion, refcount); ioc->complete(ioc->data); kfree(ioc); } static void nfs_io_completion_get(struct nfs_io_completion *ioc) { if (ioc != NULL) kref_get(&ioc->refcount); } static void nfs_io_completion_put(struct nfs_io_completion *ioc) { if (ioc != NULL) kref_put(&ioc->refcount, nfs_io_completion_release); } static void nfs_page_set_inode_ref(struct nfs_page *req, struct inode *inode) { if (!test_and_set_bit(PG_INODE_REF, &req->wb_flags)) { kref_get(&req->wb_kref); atomic_long_inc(&NFS_I(inode)->nrequests); } } static int nfs_cancel_remove_inode(struct nfs_page *req, struct inode *inode) { int ret; if (!test_bit(PG_REMOVE, &req->wb_flags)) return 0; ret = nfs_page_group_lock(req); if (ret) return ret; if (test_and_clear_bit(PG_REMOVE, &req->wb_flags)) nfs_page_set_inode_ref(req, inode); nfs_page_group_unlock(req); return 0; } /** * nfs_folio_find_head_request - find head request associated with a folio * @folio: pointer to folio * * must be called while holding the inode lock. * * returns matching head request with reference held, or NULL if not found. */ static struct nfs_page *nfs_folio_find_head_request(struct folio *folio) { struct address_space *mapping = folio->mapping; struct nfs_page *req; if (!folio_test_private(folio)) return NULL; spin_lock(&mapping->i_private_lock); req = folio->private; if (req) { WARN_ON_ONCE(req->wb_head != req); kref_get(&req->wb_kref); } spin_unlock(&mapping->i_private_lock); return req; } /* Adjust the file length if we're writing beyond the end */ static void nfs_grow_file(struct folio *folio, unsigned int offset, unsigned int count) { struct inode *inode = folio->mapping->host; loff_t end, i_size; pgoff_t end_index; spin_lock(&inode->i_lock); i_size = i_size_read(inode); end_index = ((i_size - 1) >> folio_shift(folio)) << folio_order(folio); if (i_size > 0 && folio->index < end_index) goto out; end = folio_pos(folio) + (loff_t)offset + (loff_t)count; if (i_size >= end) goto out; trace_nfs_size_grow(inode, end); i_size_write(inode, end); NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_SIZE; nfs_inc_stats(inode, NFSIOS_EXTENDWRITE); out: /* Atomically update timestamps if they are delegated to us. */ nfs_update_delegated_mtime_locked(inode); spin_unlock(&inode->i_lock); nfs_fscache_invalidate(inode, 0); } /* A writeback failed: mark the page as bad, and invalidate the page cache */ static void nfs_set_pageerror(struct address_space *mapping) { struct inode *inode = mapping->host; nfs_zap_mapping(mapping->host, mapping); /* Force file size revalidation */ spin_lock(&inode->i_lock); nfs_set_cache_invalid(inode, NFS_INO_REVAL_FORCED | NFS_INO_INVALID_CHANGE | NFS_INO_INVALID_SIZE); spin_unlock(&inode->i_lock); } static void nfs_mapping_set_error(struct folio *folio, int error) { struct address_space *mapping = folio->mapping; filemap_set_wb_err(mapping, error); if (mapping->host) errseq_set(&mapping->host->i_sb->s_wb_err, error == -ENOSPC ? -ENOSPC : -EIO); nfs_set_pageerror(mapping); } /* * nfs_page_group_search_locked * @head - head request of page group * @page_offset - offset into page * * Search page group with head @head to find a request that contains the * page offset @page_offset. * * Returns a pointer to the first matching nfs request, or NULL if no * match is found. * * Must be called with the page group lock held */ static struct nfs_page * nfs_page_group_search_locked(struct nfs_page *head, unsigned int page_offset) { struct nfs_page *req; req = head; do { if (page_offset >= req->wb_pgbase && page_offset < (req->wb_pgbase + req->wb_bytes)) return req; req = req->wb_this_page; } while (req != head); return NULL; } /* * nfs_page_group_covers_page * @head - head request of page group * * Return true if the page group with head @head covers the whole page, * returns false otherwise */ static bool nfs_page_group_covers_page(struct nfs_page *req) { unsigned int len = nfs_folio_length(nfs_page_to_folio(req)); struct nfs_page *tmp; unsigned int pos = 0; nfs_page_group_lock(req); for (;;) { tmp = nfs_page_group_search_locked(req->wb_head, pos); if (!tmp) break; pos = tmp->wb_pgbase + tmp->wb_bytes; } nfs_page_group_unlock(req); return pos >= len; } /* We can set the PG_uptodate flag if we see that a write request * covers the full page. */ static void nfs_mark_uptodate(struct nfs_page *req) { struct folio *folio = nfs_page_to_folio(req); if (folio_test_uptodate(folio)) return; if (!nfs_page_group_covers_page(req)) return; folio_mark_uptodate(folio); } static int wb_priority(struct writeback_control *wbc) { int ret = 0; if (wbc->sync_mode == WB_SYNC_ALL) ret = FLUSH_COND_STABLE; return ret; } /* * NFS congestion control */ int nfs_congestion_kb; #define NFS_CONGESTION_ON_THRESH (nfs_congestion_kb >> (PAGE_SHIFT-10)) #define NFS_CONGESTION_OFF_THRESH \ (NFS_CONGESTION_ON_THRESH - (NFS_CONGESTION_ON_THRESH >> 2)) static void nfs_folio_set_writeback(struct folio *folio) { struct nfs_server *nfss = NFS_SERVER(folio->mapping->host); folio_start_writeback(folio); if (atomic_long_inc_return(&nfss->writeback) > NFS_CONGESTION_ON_THRESH) nfss->write_congested = 1; } static void nfs_folio_end_writeback(struct folio *folio) { struct nfs_server *nfss = NFS_SERVER(folio->mapping->host); folio_end_writeback(folio); if (atomic_long_dec_return(&nfss->writeback) < NFS_CONGESTION_OFF_THRESH) { nfss->write_congested = 0; wake_up_all(&nfss->write_congestion_wait); } } static void nfs_page_end_writeback(struct nfs_page *req) { if (nfs_page_group_sync_on_bit(req, PG_WB_END)) { nfs_unlock_request(req); nfs_folio_end_writeback(nfs_page_to_folio(req)); } else nfs_unlock_request(req); } /* * nfs_destroy_unlinked_subrequests - destroy recently unlinked subrequests * * @destroy_list - request list (using wb_this_page) terminated by @old_head * @old_head - the old head of the list * * All subrequests must be locked and removed from all lists, so at this point * they are only "active" in this function, and possibly in nfs_wait_on_request * with a reference held by some other context. */ static void nfs_destroy_unlinked_subrequests(struct nfs_page *destroy_list, struct nfs_page *old_head, struct inode *inode) { while (destroy_list) { struct nfs_page *subreq = destroy_list; destroy_list = (subreq->wb_this_page == old_head) ? NULL : subreq->wb_this_page; /* Note: lock subreq in order to change subreq->wb_head */ nfs_page_set_headlock(subreq); WARN_ON_ONCE(old_head != subreq->wb_head); /* make sure old group is not used */ subreq->wb_this_page = subreq; subreq->wb_head = subreq; clear_bit(PG_REMOVE, &subreq->wb_flags); /* Note: races with nfs_page_group_destroy() */ if (!kref_read(&subreq->wb_kref)) { /* Check if we raced with nfs_page_group_destroy() */ if (test_and_clear_bit(PG_TEARDOWN, &subreq->wb_flags)) { nfs_page_clear_headlock(subreq); nfs_free_request(subreq); } else nfs_page_clear_headlock(subreq); continue; } nfs_page_clear_headlock(subreq); nfs_release_request(old_head); if (test_and_clear_bit(PG_INODE_REF, &subreq->wb_flags)) { nfs_release_request(subreq); atomic_long_dec(&NFS_I(inode)->nrequests); } /* subreq is now totally disconnected from page group or any * write / commit lists. last chance to wake any waiters */ nfs_unlock_and_release_request(subreq); } } /* * nfs_join_page_group - destroy subrequests of the head req * @head: the page used to lookup the "page group" of nfs_page structures * @inode: Inode to which the request belongs. * * This function joins all sub requests to the head request by first * locking all requests in the group, cancelling any pending operations * and finally updating the head request to cover the whole range covered by * the (former) group. All subrequests are removed from any write or commit * lists, unlinked from the group and destroyed. */ void nfs_join_page_group(struct nfs_page *head, struct nfs_commit_info *cinfo, struct inode *inode) { struct nfs_page *subreq; struct nfs_page *destroy_list = NULL; unsigned int pgbase, off, bytes; pgbase = head->wb_pgbase; bytes = head->wb_bytes; off = head->wb_offset; for (subreq = head->wb_this_page; subreq != head; subreq = subreq->wb_this_page) { /* Subrequests should always form a contiguous range */ if (pgbase > subreq->wb_pgbase) { off -= pgbase - subreq->wb_pgbase; bytes += pgbase - subreq->wb_pgbase; pgbase = subreq->wb_pgbase; } bytes = max(subreq->wb_pgbase + subreq->wb_bytes - pgbase, bytes); } /* Set the head request's range to cover the former page group */ head->wb_pgbase = pgbase; head->wb_bytes = bytes; head->wb_offset = off; /* Now that all requests are locked, make sure they aren't on any list. * Commit list removal accounting is done after locks are dropped */ subreq = head; do { nfs_clear_request_commit(cinfo, subreq); subreq = subreq->wb_this_page; } while (subreq != head); /* unlink subrequests from head, destroy them later */ if (head->wb_this_page != head) { /* destroy list will be terminated by head */ destroy_list = head->wb_this_page; head->wb_this_page = head; } nfs_destroy_unlinked_subrequests(destroy_list, head, inode); } /** * nfs_wait_on_request - Wait for a request to complete. * @req: request to wait upon. * * Interruptible by fatal signals only. * The user is responsible for holding a count on the request. */ static int nfs_wait_on_request(struct nfs_page *req) { if (!test_bit(PG_BUSY, &req->wb_flags)) return 0; set_bit(PG_CONTENDED2, &req->wb_flags); smp_mb__after_atomic(); return wait_on_bit_io(&req->wb_flags, PG_BUSY, TASK_UNINTERRUPTIBLE); } /* * nfs_unroll_locks - unlock all newly locked reqs and wait on @req * @head: head request of page group, must be holding head lock * @req: request that couldn't lock and needs to wait on the req bit lock * * This is a helper function for nfs_lock_and_join_requests * returns 0 on success, < 0 on error. */ static void nfs_unroll_locks(struct nfs_page *head, struct nfs_page *req) { struct nfs_page *tmp; /* relinquish all the locks successfully grabbed this run */ for (tmp = head->wb_this_page ; tmp != req; tmp = tmp->wb_this_page) { if (!kref_read(&tmp->wb_kref)) continue; nfs_unlock_and_release_request(tmp); } } /* * nfs_page_group_lock_subreq - try to lock a subrequest * @head: head request of page group * @subreq: request to lock * * This is a helper function for nfs_lock_and_join_requests which * must be called with the head request and page group both locked. * On error, it returns with the page group unlocked. */ static int nfs_page_group_lock_subreq(struct nfs_page *head, struct nfs_page *subreq) { int ret; if (!kref_get_unless_zero(&subreq->wb_kref)) return 0; while (!nfs_lock_request(subreq)) { nfs_page_group_unlock(head); ret = nfs_wait_on_request(subreq); if (!ret) ret = nfs_page_group_lock(head); if (ret < 0) { nfs_unroll_locks(head, subreq); nfs_release_request(subreq); return ret; } } return 0; } /* * nfs_lock_and_join_requests - join all subreqs to the head req * @folio: the folio used to lookup the "page group" of nfs_page structures * * This function joins all sub requests to the head request by first * locking all requests in the group, cancelling any pending operations * and finally updating the head request to cover the whole range covered by * the (former) group. All subrequests are removed from any write or commit * lists, unlinked from the group and destroyed. * * Returns a locked, referenced pointer to the head request - which after * this call is guaranteed to be the only request associated with the page. * Returns NULL if no requests are found for @folio, or a ERR_PTR if an * error was encountered. */ static struct nfs_page *nfs_lock_and_join_requests(struct folio *folio) { struct inode *inode = folio->mapping->host; struct nfs_page *head, *subreq; struct nfs_commit_info cinfo; int ret; /* * A reference is taken only on the head request which acts as a * reference to the whole page group - the group will not be destroyed * until the head reference is released. */ retry: head = nfs_folio_find_head_request(folio); if (!head) return NULL; while (!nfs_lock_request(head)) { ret = nfs_wait_on_request(head); if (ret < 0) return ERR_PTR(ret); } /* Ensure that nobody removed the request before we locked it */ if (head != folio->private) { nfs_unlock_and_release_request(head); goto retry; } ret = nfs_cancel_remove_inode(head, inode); if (ret < 0) goto out_unlock; ret = nfs_page_group_lock(head); if (ret < 0) goto out_unlock; /* lock each request in the page group */ for (subreq = head->wb_this_page; subreq != head; subreq = subreq->wb_this_page) { ret = nfs_page_group_lock_subreq(head, subreq); if (ret < 0) goto out_unlock; } nfs_page_group_unlock(head); nfs_init_cinfo_from_inode(&cinfo, inode); nfs_join_page_group(head, &cinfo, inode); return head; out_unlock: nfs_unlock_and_release_request(head); return ERR_PTR(ret); } static void nfs_write_error(struct nfs_page *req, int error) { trace_nfs_write_error(nfs_page_to_inode(req), req, error); nfs_mapping_set_error(nfs_page_to_folio(req), error); nfs_inode_remove_request(req); nfs_page_end_writeback(req); nfs_release_request(req); } /* * Find an associated nfs write request, and prepare to flush it out * May return an error if the user signalled nfs_wait_on_request(). */ static int nfs_page_async_flush(struct folio *folio, struct writeback_control *wbc, struct nfs_pageio_descriptor *pgio) { struct nfs_page *req; int ret = 0; req = nfs_lock_and_join_requests(folio); if (!req) goto out; ret = PTR_ERR(req); if (IS_ERR(req)) goto out; nfs_folio_set_writeback(folio); WARN_ON_ONCE(test_bit(PG_CLEAN, &req->wb_flags)); /* If there is a fatal error that covers this write, just exit */ ret = pgio->pg_error; if (nfs_error_is_fatal_on_server(ret)) goto out_launder; ret = 0; if (!nfs_pageio_add_request(pgio, req)) { ret = pgio->pg_error; /* * Remove the problematic req upon fatal errors on the server */ if (nfs_error_is_fatal_on_server(ret)) goto out_launder; if (wbc->sync_mode == WB_SYNC_NONE) ret = AOP_WRITEPAGE_ACTIVATE; folio_redirty_for_writepage(wbc, folio); nfs_redirty_request(req); pgio->pg_error = 0; } else nfs_add_stats(folio->mapping->host, NFSIOS_WRITEPAGES, 1); out: return ret; out_launder: nfs_write_error(req, ret); return 0; } static int nfs_do_writepage(struct folio *folio, struct writeback_control *wbc, struct nfs_pageio_descriptor *pgio) { nfs_pageio_cond_complete(pgio, folio->index); return nfs_page_async_flush(folio, wbc, pgio); } /* * Write an mmapped page to the server. */ static int nfs_writepage_locked(struct folio *folio, struct writeback_control *wbc) { struct nfs_pageio_descriptor pgio; struct inode *inode = folio->mapping->host; int err; nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGE); nfs_pageio_init_write(&pgio, inode, 0, false, &nfs_async_write_completion_ops); err = nfs_do_writepage(folio, wbc, &pgio); pgio.pg_error = 0; nfs_pageio_complete(&pgio); return err; } static int nfs_writepages_callback(struct folio *folio, struct writeback_control *wbc, void *data) { int ret; ret = nfs_do_writepage(folio, wbc, data); if (ret != AOP_WRITEPAGE_ACTIVATE) folio_unlock(folio); return ret; } static void nfs_io_completion_commit(void *inode) { nfs_commit_inode(inode, 0); } int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc) { struct inode *inode = mapping->host; struct nfs_pageio_descriptor pgio; struct nfs_io_completion *ioc = NULL; unsigned int mntflags = NFS_SERVER(inode)->flags; struct nfs_server *nfss = NFS_SERVER(inode); int priority = 0; int err; /* Wait with writeback until write congestion eases */ if (wbc->sync_mode == WB_SYNC_NONE && nfss->write_congested) { err = wait_event_killable(nfss->write_congestion_wait, nfss->write_congested == 0); if (err) return err; } nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGES); if (!(mntflags & NFS_MOUNT_WRITE_EAGER) || wbc->for_kupdate || wbc->for_background || wbc->for_sync || wbc->for_reclaim) { ioc = nfs_io_completion_alloc(GFP_KERNEL); if (ioc) nfs_io_completion_init(ioc, nfs_io_completion_commit, inode); priority = wb_priority(wbc); } do { nfs_pageio_init_write(&pgio, inode, priority, false, &nfs_async_write_completion_ops); pgio.pg_io_completion = ioc; err = write_cache_pages(mapping, wbc, nfs_writepages_callback, &pgio); pgio.pg_error = 0; nfs_pageio_complete(&pgio); if (err == -EAGAIN && mntflags & NFS_MOUNT_SOFTERR) break; } while (err < 0 && !nfs_error_is_fatal(err)); nfs_io_completion_put(ioc); if (err < 0) goto out_err; return 0; out_err: return err; } /* * Insert a write request into an inode */ static void nfs_inode_add_request(struct nfs_page *req) { struct folio *folio = nfs_page_to_folio(req); struct address_space *mapping = folio->mapping; struct nfs_inode *nfsi = NFS_I(mapping->host); WARN_ON_ONCE(req->wb_this_page != req); /* Lock the request! */ nfs_lock_request(req); spin_lock(&mapping->i_private_lock); set_bit(PG_MAPPED, &req->wb_flags); folio_set_private(folio); folio->private = req; spin_unlock(&mapping->i_private_lock); atomic_long_inc(&nfsi->nrequests); /* this a head request for a page group - mark it as having an * extra reference so sub groups can follow suit. * This flag also informs pgio layer when to bump nrequests when * adding subrequests. */ WARN_ON(test_and_set_bit(PG_INODE_REF, &req->wb_flags)); kref_get(&req->wb_kref); } /* * Remove a write request from an inode */ static void nfs_inode_remove_request(struct nfs_page *req) { struct nfs_inode *nfsi = NFS_I(nfs_page_to_inode(req)); if (nfs_page_group_sync_on_bit(req, PG_REMOVE)) { struct folio *folio = nfs_page_to_folio(req->wb_head); struct address_space *mapping = folio->mapping; spin_lock(&mapping->i_private_lock); if (likely(folio)) { folio->private = NULL; folio_clear_private(folio); clear_bit(PG_MAPPED, &req->wb_head->wb_flags); } spin_unlock(&mapping->i_private_lock); } if (test_and_clear_bit(PG_INODE_REF, &req->wb_flags)) { atomic_long_dec(&nfsi->nrequests); nfs_release_request(req); } } static void nfs_mark_request_dirty(struct nfs_page *req) { struct folio *folio = nfs_page_to_folio(req); if (folio) filemap_dirty_folio(folio_mapping(folio), folio); } /** * nfs_request_add_commit_list_locked - add request to a commit list * @req: pointer to a struct nfs_page * @dst: commit list head * @cinfo: holds list lock and accounting info * * This sets the PG_CLEAN bit, updates the cinfo count of * number of outstanding requests requiring a commit as well as * the MM page stats. * * The caller must hold NFS_I(cinfo->inode)->commit_mutex, and the * nfs_page lock. */ void nfs_request_add_commit_list_locked(struct nfs_page *req, struct list_head *dst, struct nfs_commit_info *cinfo) { set_bit(PG_CLEAN, &req->wb_flags); nfs_list_add_request(req, dst); atomic_long_inc(&cinfo->mds->ncommit); } EXPORT_SYMBOL_GPL(nfs_request_add_commit_list_locked); /** * nfs_request_add_commit_list - add request to a commit list * @req: pointer to a struct nfs_page * @cinfo: holds list lock and accounting info * * This sets the PG_CLEAN bit, updates the cinfo count of * number of outstanding requests requiring a commit as well as * the MM page stats. * * The caller must _not_ hold the cinfo->lock, but must be * holding the nfs_page lock. */ void nfs_request_add_commit_list(struct nfs_page *req, struct nfs_commit_info *cinfo) { mutex_lock(&NFS_I(cinfo->inode)->commit_mutex); nfs_request_add_commit_list_locked(req, &cinfo->mds->list, cinfo); mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex); nfs_folio_mark_unstable(nfs_page_to_folio(req), cinfo); } EXPORT_SYMBOL_GPL(nfs_request_add_commit_list); /** * nfs_request_remove_commit_list - Remove request from a commit list * @req: pointer to a nfs_page * @cinfo: holds list lock and accounting info * * This clears the PG_CLEAN bit, and updates the cinfo's count of * number of outstanding requests requiring a commit * It does not update the MM page stats. * * The caller _must_ hold the cinfo->lock and the nfs_page lock. */ void nfs_request_remove_commit_list(struct nfs_page *req, struct nfs_commit_info *cinfo) { if (!test_and_clear_bit(PG_CLEAN, &(req)->wb_flags)) return; nfs_list_remove_request(req); atomic_long_dec(&cinfo->mds->ncommit); } EXPORT_SYMBOL_GPL(nfs_request_remove_commit_list); static void nfs_init_cinfo_from_inode(struct nfs_commit_info *cinfo, struct inode *inode) { cinfo->inode = inode; cinfo->mds = &NFS_I(inode)->commit_info; cinfo->ds = pnfs_get_ds_info(inode); cinfo->dreq = NULL; cinfo->completion_ops = &nfs_commit_completion_ops; } void nfs_init_cinfo(struct nfs_commit_info *cinfo, struct inode *inode, struct nfs_direct_req *dreq) { if (dreq) nfs_init_cinfo_from_dreq(cinfo, dreq); else nfs_init_cinfo_from_inode(cinfo, inode); } EXPORT_SYMBOL_GPL(nfs_init_cinfo); /* * Add a request to the inode's commit list. */ void nfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg, struct nfs_commit_info *cinfo, u32 ds_commit_idx) { if (pnfs_mark_request_commit(req, lseg, cinfo, ds_commit_idx)) return; nfs_request_add_commit_list(req, cinfo); } static void nfs_folio_clear_commit(struct folio *folio) { if (folio) { long nr = folio_nr_pages(folio); node_stat_mod_folio(folio, NR_WRITEBACK, -nr); wb_stat_mod(&inode_to_bdi(folio->mapping->host)->wb, WB_WRITEBACK, -nr); } } /* Called holding the request lock on @req */ static void nfs_clear_request_commit(struct nfs_commit_info *cinfo, struct nfs_page *req) { if (test_bit(PG_CLEAN, &req->wb_flags)) { struct nfs_open_context *ctx = nfs_req_openctx(req); struct inode *inode = d_inode(ctx->dentry); mutex_lock(&NFS_I(inode)->commit_mutex); if (!pnfs_clear_request_commit(req, cinfo)) { nfs_request_remove_commit_list(req, cinfo); } mutex_unlock(&NFS_I(inode)->commit_mutex); nfs_folio_clear_commit(nfs_page_to_folio(req)); } } int nfs_write_need_commit(struct nfs_pgio_header *hdr) { if (hdr->verf.committed == NFS_DATA_SYNC) return hdr->lseg == NULL; return hdr->verf.committed != NFS_FILE_SYNC; } static void nfs_async_write_init(struct nfs_pgio_header *hdr) { nfs_io_completion_get(hdr->io_completion); } static void nfs_write_completion(struct nfs_pgio_header *hdr) { struct nfs_commit_info cinfo; unsigned long bytes = 0; if (test_bit(NFS_IOHDR_REDO, &hdr->flags)) goto out; nfs_init_cinfo_from_inode(&cinfo, hdr->inode); while (!list_empty(&hdr->pages)) { struct nfs_page *req = nfs_list_entry(hdr->pages.next); bytes += req->wb_bytes; nfs_list_remove_request(req); if (test_bit(NFS_IOHDR_ERROR, &hdr->flags) && (hdr->good_bytes < bytes)) { trace_nfs_comp_error(hdr->inode, req, hdr->error); nfs_mapping_set_error(nfs_page_to_folio(req), hdr->error); goto remove_req; } if (nfs_write_need_commit(hdr)) { /* Reset wb_nio, since the write was successful. */ req->wb_nio = 0; memcpy(&req->wb_verf, &hdr->verf.verifier, sizeof(req->wb_verf)); nfs_mark_request_commit(req, hdr->lseg, &cinfo, hdr->pgio_mirror_idx); goto next; } remove_req: nfs_inode_remove_request(req); next: nfs_page_end_writeback(req); nfs_release_request(req); } out: nfs_io_completion_put(hdr->io_completion); hdr->release(hdr); } unsigned long nfs_reqs_to_commit(struct nfs_commit_info *cinfo) { return atomic_long_read(&cinfo->mds->ncommit); } /* NFS_I(cinfo->inode)->commit_mutex held by caller */ int nfs_scan_commit_list(struct list_head *src, struct list_head *dst, struct nfs_commit_info *cinfo, int max) { struct nfs_page *req, *tmp; int ret = 0; list_for_each_entry_safe(req, tmp, src, wb_list) { kref_get(&req->wb_kref); if (!nfs_lock_request(req)) { nfs_release_request(req); continue; } nfs_request_remove_commit_list(req, cinfo); clear_bit(PG_COMMIT_TO_DS, &req->wb_flags); nfs_list_add_request(req, dst); ret++; if ((ret == max) && !cinfo->dreq) break; cond_resched(); } return ret; } EXPORT_SYMBOL_GPL(nfs_scan_commit_list); /* * nfs_scan_commit - Scan an inode for commit requests * @inode: NFS inode to scan * @dst: mds destination list * @cinfo: mds and ds lists of reqs ready to commit * * Moves requests from the inode's 'commit' request list. * The requests are *not* checked to ensure that they form a contiguous set. */ int nfs_scan_commit(struct inode *inode, struct list_head *dst, struct nfs_commit_info *cinfo) { int ret = 0; if (!atomic_long_read(&cinfo->mds->ncommit)) return 0; mutex_lock(&NFS_I(cinfo->inode)->commit_mutex); if (atomic_long_read(&cinfo->mds->ncommit) > 0) { const int max = INT_MAX; ret = nfs_scan_commit_list(&cinfo->mds->list, dst, cinfo, max); ret += pnfs_scan_commit_lists(inode, cinfo, max - ret); } mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex); return ret; } /* * Search for an existing write request, and attempt to update * it to reflect a new dirty region on a given page. * * If the attempt fails, then the existing request is flushed out * to disk. */ static struct nfs_page *nfs_try_to_update_request(struct folio *folio, unsigned int offset, unsigned int bytes) { struct nfs_page *req; unsigned int rqend; unsigned int end; int error; end = offset + bytes; req = nfs_lock_and_join_requests(folio); if (IS_ERR_OR_NULL(req)) return req; rqend = req->wb_offset + req->wb_bytes; /* * Tell the caller to flush out the request if * the offsets are non-contiguous. * Note: nfs_flush_incompatible() will already * have flushed out requests having wrong owners. */ if (offset > rqend || end < req->wb_offset) goto out_flushme; /* Okay, the request matches. Update the region */ if (offset < req->wb_offset) { req->wb_offset = offset; req->wb_pgbase = offset; } if (end > rqend) req->wb_bytes = end - req->wb_offset; else req->wb_bytes = rqend - req->wb_offset; req->wb_nio = 0; return req; out_flushme: /* * Note: we mark the request dirty here because * nfs_lock_and_join_requests() cannot preserve * commit flags, so we have to replay the write. */ nfs_mark_request_dirty(req); nfs_unlock_and_release_request(req); error = nfs_wb_folio(folio->mapping->host, folio); return (error < 0) ? ERR_PTR(error) : NULL; } /* * Try to update an existing write request, or create one if there is none. * * Note: Should always be called with the Page Lock held to prevent races * if we have to add a new request. Also assumes that the caller has * already called nfs_flush_incompatible() if necessary. */ static struct nfs_page *nfs_setup_write_request(struct nfs_open_context *ctx, struct folio *folio, unsigned int offset, unsigned int bytes) { struct nfs_page *req; req = nfs_try_to_update_request(folio, offset, bytes); if (req != NULL) goto out; req = nfs_page_create_from_folio(ctx, folio, offset, bytes); if (IS_ERR(req)) goto out; nfs_inode_add_request(req); out: return req; } static int nfs_writepage_setup(struct nfs_open_context *ctx, struct folio *folio, unsigned int offset, unsigned int count) { struct nfs_page *req; req = nfs_setup_write_request(ctx, folio, offset, count); if (IS_ERR(req)) return PTR_ERR(req); /* Update file length */ nfs_grow_file(folio, offset, count); nfs_mark_uptodate(req); nfs_mark_request_dirty(req); nfs_unlock_and_release_request(req); return 0; } int nfs_flush_incompatible(struct file *file, struct folio *folio) { struct nfs_open_context *ctx = nfs_file_open_context(file); struct nfs_lock_context *l_ctx; struct file_lock_context *flctx = locks_inode_context(file_inode(file)); struct nfs_page *req; int do_flush, status; /* * Look for a request corresponding to this page. If there * is one, and it belongs to another file, we flush it out * before we try to copy anything into the page. Do this * due to the lack of an ACCESS-type call in NFSv2. * Also do the same if we find a request from an existing * dropped page. */ do { req = nfs_folio_find_head_request(folio); if (req == NULL) return 0; l_ctx = req->wb_lock_context; do_flush = nfs_page_to_folio(req) != folio || !nfs_match_open_context(nfs_req_openctx(req), ctx); if (l_ctx && flctx && !(list_empty_careful(&flctx->flc_posix) && list_empty_careful(&flctx->flc_flock))) { do_flush |= l_ctx->lockowner != current->files; } nfs_release_request(req); if (!do_flush) return 0; status = nfs_wb_folio(folio->mapping->host, folio); } while (status == 0); return status; } /* * Avoid buffered writes when a open context credential's key would * expire soon. * * Returns -EACCES if the key will expire within RPC_KEY_EXPIRE_FAIL. * * Return 0 and set a credential flag which triggers the inode to flush * and performs NFS_FILE_SYNC writes if the key will expired within * RPC_KEY_EXPIRE_TIMEO. */ int nfs_key_timeout_notify(struct file *filp, struct inode *inode) { struct nfs_open_context *ctx = nfs_file_open_context(filp); if (nfs_ctx_key_to_expire(ctx, inode) && !rcu_access_pointer(ctx->ll_cred)) /* Already expired! */ return -EACCES; return 0; } /* * Test if the open context credential key is marked to expire soon. */ bool nfs_ctx_key_to_expire(struct nfs_open_context *ctx, struct inode *inode) { struct rpc_auth *auth = NFS_SERVER(inode)->client->cl_auth; struct rpc_cred *cred, *new, *old = NULL; struct auth_cred acred = { .cred = ctx->cred, }; bool ret = false; rcu_read_lock(); cred = rcu_dereference(ctx->ll_cred); if (cred && !(cred->cr_ops->crkey_timeout && cred->cr_ops->crkey_timeout(cred))) goto out; rcu_read_unlock(); new = auth->au_ops->lookup_cred(auth, &acred, 0); if (new == cred) { put_rpccred(new); return true; } if (IS_ERR_OR_NULL(new)) { new = NULL; ret = true; } else if (new->cr_ops->crkey_timeout && new->cr_ops->crkey_timeout(new)) ret = true; rcu_read_lock(); old = rcu_dereference_protected(xchg(&ctx->ll_cred, RCU_INITIALIZER(new)), 1); out: rcu_read_unlock(); put_rpccred(old); return ret; } /* * If the page cache is marked as unsafe or invalid, then we can't rely on * the PageUptodate() flag. In this case, we will need to turn off * write optimisations that depend on the page contents being correct. */ static bool nfs_folio_write_uptodate(struct folio *folio, unsigned int pagelen) { struct inode *inode = folio->mapping->host; struct nfs_inode *nfsi = NFS_I(inode); if (nfs_have_delegated_attributes(inode)) goto out; if (nfsi->cache_validity & (NFS_INO_INVALID_CHANGE | NFS_INO_INVALID_SIZE)) return false; smp_rmb(); if (test_bit(NFS_INO_INVALIDATING, &nfsi->flags) && pagelen != 0) return false; out: if (nfsi->cache_validity & NFS_INO_INVALID_DATA && pagelen != 0) return false; return folio_test_uptodate(folio) != 0; } static bool is_whole_file_wrlock(struct file_lock *fl) { return fl->fl_start == 0 && fl->fl_end == OFFSET_MAX && lock_is_write(fl); } /* If we know the page is up to date, and we're not using byte range locks (or * if we have the whole file locked for writing), it may be more efficient to * extend the write to cover the entire page in order to avoid fragmentation * inefficiencies. * * If the file is opened for synchronous writes then we can just skip the rest * of the checks. */ static int nfs_can_extend_write(struct file *file, struct folio *folio, unsigned int pagelen) { struct inode *inode = file_inode(file); struct file_lock_context *flctx = locks_inode_context(inode); struct file_lock *fl; int ret; unsigned int mntflags = NFS_SERVER(inode)->flags; if (mntflags & NFS_MOUNT_NO_ALIGNWRITE) return 0; if (file->f_flags & O_DSYNC) return 0; if (!nfs_folio_write_uptodate(folio, pagelen)) return 0; if (nfs_have_write_delegation(inode)) return 1; if (!flctx || (list_empty_careful(&flctx->flc_flock) && list_empty_careful(&flctx->flc_posix))) return 1; /* Check to see if there are whole file write locks */ ret = 0; spin_lock(&flctx->flc_lock); if (!list_empty(&flctx->flc_posix)) { fl = list_first_entry(&flctx->flc_posix, struct file_lock, c.flc_list); if (is_whole_file_wrlock(fl)) ret = 1; } else if (!list_empty(&flctx->flc_flock)) { fl = list_first_entry(&flctx->flc_flock, struct file_lock, c.flc_list); if (lock_is_write(fl)) ret = 1; } spin_unlock(&flctx->flc_lock); return ret; } /* * Update and possibly write a cached page of an NFS file. * * XXX: Keep an eye on generic_file_read to make sure it doesn't do bad * things with a page scheduled for an RPC call (e.g. invalidate it). */ int nfs_update_folio(struct file *file, struct folio *folio, unsigned int offset, unsigned int count) { struct nfs_open_context *ctx = nfs_file_open_context(file); struct address_space *mapping = folio->mapping; struct inode *inode = mapping->host; unsigned int pagelen = nfs_folio_length(folio); int status = 0; nfs_inc_stats(inode, NFSIOS_VFSUPDATEPAGE); dprintk("NFS: nfs_update_folio(%pD2 %d@%lld)\n", file, count, (long long)(folio_pos(folio) + offset)); if (!count) goto out; if (nfs_can_extend_write(file, folio, pagelen)) { unsigned int end = count + offset; offset = round_down(offset, PAGE_SIZE); if (end < pagelen) end = min(round_up(end, PAGE_SIZE), pagelen); count = end - offset; } status = nfs_writepage_setup(ctx, folio, offset, count); if (status < 0) nfs_set_pageerror(mapping); out: dprintk("NFS: nfs_update_folio returns %d (isize %lld)\n", status, (long long)i_size_read(inode)); return status; } static int flush_task_priority(int how) { switch (how & (FLUSH_HIGHPRI|FLUSH_LOWPRI)) { case FLUSH_HIGHPRI: return RPC_PRIORITY_HIGH; case FLUSH_LOWPRI: return RPC_PRIORITY_LOW; } return RPC_PRIORITY_NORMAL; } static void nfs_initiate_write(struct nfs_pgio_header *hdr, struct rpc_message *msg, const struct nfs_rpc_ops *rpc_ops, struct rpc_task_setup *task_setup_data, int how) { int priority = flush_task_priority(how); if (IS_SWAPFILE(hdr->inode)) task_setup_data->flags |= RPC_TASK_SWAPPER; task_setup_data->priority = priority; rpc_ops->write_setup(hdr, msg, &task_setup_data->rpc_client); trace_nfs_initiate_write(hdr); } /* If a nfs_flush_* function fails, it should remove reqs from @head and * call this on each, which will prepare them to be retried on next * writeback using standard nfs. */ static void nfs_redirty_request(struct nfs_page *req) { struct nfs_inode *nfsi = NFS_I(nfs_page_to_inode(req)); /* Bump the transmission count */ req->wb_nio++; nfs_mark_request_dirty(req); atomic_long_inc(&nfsi->redirtied_pages); nfs_page_end_writeback(req); nfs_release_request(req); } static void nfs_async_write_error(struct list_head *head, int error) { struct nfs_page *req; while (!list_empty(head)) { req = nfs_list_entry(head->next); nfs_list_remove_request(req); if (nfs_error_is_fatal_on_server(error)) nfs_write_error(req, error); else nfs_redirty_request(req); } } static void nfs_async_write_reschedule_io(struct nfs_pgio_header *hdr) { nfs_async_write_error(&hdr->pages, 0); } static const struct nfs_pgio_completion_ops nfs_async_write_completion_ops = { .init_hdr = nfs_async_write_init, .error_cleanup = nfs_async_write_error, .completion = nfs_write_completion, .reschedule_io = nfs_async_write_reschedule_io, }; void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio, struct inode *inode, int ioflags, bool force_mds, const struct nfs_pgio_completion_ops *compl_ops) { struct nfs_server *server = NFS_SERVER(inode); const struct nfs_pageio_ops *pg_ops = &nfs_pgio_rw_ops; #ifdef CONFIG_NFS_V4_1 if (server->pnfs_curr_ld && !force_mds) pg_ops = server->pnfs_curr_ld->pg_write_ops; #endif nfs_pageio_init(pgio, inode, pg_ops, compl_ops, &nfs_rw_write_ops, server->wsize, ioflags); } EXPORT_SYMBOL_GPL(nfs_pageio_init_write); void nfs_pageio_reset_write_mds(struct nfs_pageio_descriptor *pgio) { struct nfs_pgio_mirror *mirror; if (pgio->pg_ops && pgio->pg_ops->pg_cleanup) pgio->pg_ops->pg_cleanup(pgio); pgio->pg_ops = &nfs_pgio_rw_ops; nfs_pageio_stop_mirroring(pgio); mirror = &pgio->pg_mirrors[0]; mirror->pg_bsize = NFS_SERVER(pgio->pg_inode)->wsize; } EXPORT_SYMBOL_GPL(nfs_pageio_reset_write_mds); void nfs_commit_prepare(struct rpc_task *task, void *calldata) { struct nfs_commit_data *data = calldata; NFS_PROTO(data->inode)->commit_rpc_prepare(task, data); } static void nfs_writeback_check_extend(struct nfs_pgio_header *hdr, struct nfs_fattr *fattr) { struct nfs_pgio_args *argp = &hdr->args; struct nfs_pgio_res *resp = &hdr->res; u64 size = argp->offset + resp->count; if (!(fattr->valid & NFS_ATTR_FATTR_SIZE)) fattr->size = size; if (nfs_size_to_loff_t(fattr->size) < i_size_read(hdr->inode)) { fattr->valid &= ~NFS_ATTR_FATTR_SIZE; return; } if (size != fattr->size) return; /* Set attribute barrier */ nfs_fattr_set_barrier(fattr); /* ...and update size */ fattr->valid |= NFS_ATTR_FATTR_SIZE; } void nfs_writeback_update_inode(struct nfs_pgio_header *hdr) { struct nfs_fattr *fattr = &hdr->fattr; struct inode *inode = hdr->inode; if (nfs_have_delegated_mtime(inode)) { spin_lock(&inode->i_lock); nfs_set_cache_invalid(inode, NFS_INO_INVALID_BLOCKS); spin_unlock(&inode->i_lock); return; } spin_lock(&inode->i_lock); nfs_writeback_check_extend(hdr, fattr); nfs_post_op_update_inode_force_wcc_locked(inode, fattr); spin_unlock(&inode->i_lock); } EXPORT_SYMBOL_GPL(nfs_writeback_update_inode); /* * This function is called when the WRITE call is complete. */ static int nfs_writeback_done(struct rpc_task *task, struct nfs_pgio_header *hdr, struct inode *inode) { int status; /* * ->write_done will attempt to use post-op attributes to detect * conflicting writes by other clients. A strict interpretation * of close-to-open would allow us to continue caching even if * another writer had changed the file, but some applications * depend on tighter cache coherency when writing. */ status = NFS_PROTO(inode)->write_done(task, hdr); if (status != 0) return status; nfs_add_stats(inode, NFSIOS_SERVERWRITTENBYTES, hdr->res.count); trace_nfs_writeback_done(task, hdr); if (task->tk_status >= 0) { enum nfs3_stable_how committed = hdr->res.verf->committed; if (committed == NFS_UNSTABLE) { /* * We have some uncommitted data on the server at * this point, so ensure that we keep track of that * fact irrespective of what later writes do. */ set_bit(NFS_IOHDR_UNSTABLE_WRITES, &hdr->flags); } if (committed < hdr->args.stable) { /* We tried a write call, but the server did not * commit data to stable storage even though we * requested it. * Note: There is a known bug in Tru64 < 5.0 in which * the server reports NFS_DATA_SYNC, but performs * NFS_FILE_SYNC. We therefore implement this checking * as a dprintk() in order to avoid filling syslog. */ static unsigned long complain; /* Note this will print the MDS for a DS write */ if (time_before(complain, jiffies)) { dprintk("NFS: faulty NFS server %s:" " (committed = %d) != (stable = %d)\n", NFS_SERVER(inode)->nfs_client->cl_hostname, committed, hdr->args.stable); complain = jiffies + 300 * HZ; } } } /* Deal with the suid/sgid bit corner case */ if (nfs_should_remove_suid(inode)) { spin_lock(&inode->i_lock); nfs_set_cache_invalid(inode, NFS_INO_INVALID_MODE); spin_unlock(&inode->i_lock); } return 0; } /* * This function is called when the WRITE call is complete. */ static void nfs_writeback_result(struct rpc_task *task, struct nfs_pgio_header *hdr) { struct nfs_pgio_args *argp = &hdr->args; struct nfs_pgio_res *resp = &hdr->res; if (resp->count < argp->count) { static unsigned long complain; /* This a short write! */ nfs_inc_stats(hdr->inode, NFSIOS_SHORTWRITE); /* Has the server at least made some progress? */ if (resp->count == 0) { if (time_before(complain, jiffies)) { printk(KERN_WARNING "NFS: Server wrote zero bytes, expected %u.\n", argp->count); complain = jiffies + 300 * HZ; } nfs_set_pgio_error(hdr, -EIO, argp->offset); task->tk_status = -EIO; return; } /* For non rpc-based layout drivers, retry-through-MDS */ if (!task->tk_ops) { hdr->pnfs_error = -EAGAIN; return; } /* Was this an NFSv2 write or an NFSv3 stable write? */ if (resp->verf->committed != NFS_UNSTABLE) { /* Resend from where the server left off */ hdr->mds_offset += resp->count; argp->offset += resp->count; argp->pgbase += resp->count; argp->count -= resp->count; } else { /* Resend as a stable write in order to avoid * headaches in the case of a server crash. */ argp->stable = NFS_FILE_SYNC; } resp->count = 0; resp->verf->committed = 0; rpc_restart_call_prepare(task); } } static int wait_on_commit(struct nfs_mds_commit_info *cinfo) { return wait_var_event_killable(&cinfo->rpcs_out, !atomic_read(&cinfo->rpcs_out)); } void nfs_commit_begin(struct nfs_mds_commit_info *cinfo) { atomic_inc(&cinfo->rpcs_out); } bool nfs_commit_end(struct nfs_mds_commit_info *cinfo) { if (atomic_dec_and_test(&cinfo->rpcs_out)) { wake_up_var(&cinfo->rpcs_out); return true; } return false; } void nfs_commitdata_release(struct nfs_commit_data *data) { put_nfs_open_context(data->context); nfs_commit_free(data); } EXPORT_SYMBOL_GPL(nfs_commitdata_release); int nfs_initiate_commit(struct rpc_clnt *clnt, struct nfs_commit_data *data, const struct nfs_rpc_ops *nfs_ops, const struct rpc_call_ops *call_ops, int how, int flags, struct nfsd_file *localio) { struct rpc_task *task; int priority = flush_task_priority(how); struct rpc_message msg = { .rpc_argp = &data->args, .rpc_resp = &data->res, .rpc_cred = data->cred, }; struct rpc_task_setup task_setup_data = { .task = &data->task, .rpc_client = clnt, .rpc_message = &msg, .callback_ops = call_ops, .callback_data = data, .workqueue = nfsiod_workqueue, .flags = RPC_TASK_ASYNC | flags, .priority = priority, }; if (nfs_server_capable(data->inode, NFS_CAP_MOVEABLE)) task_setup_data.flags |= RPC_TASK_MOVEABLE; /* Set up the initial task struct. */ nfs_ops->commit_setup(data, &msg, &task_setup_data.rpc_client); trace_nfs_initiate_commit(data); dprintk("NFS: initiated commit call\n"); if (localio) return nfs_local_commit(localio, data, call_ops, how); task = rpc_run_task(&task_setup_data); if (IS_ERR(task)) return PTR_ERR(task); if (how & FLUSH_SYNC) rpc_wait_for_completion_task(task); rpc_put_task(task); return 0; } EXPORT_SYMBOL_GPL(nfs_initiate_commit); static loff_t nfs_get_lwb(struct list_head *head) { loff_t lwb = 0; struct nfs_page *req; list_for_each_entry(req, head, wb_list) if (lwb < (req_offset(req) + req->wb_bytes)) lwb = req_offset(req) + req->wb_bytes; return lwb; } /* * Set up the argument/result storage required for the RPC call. */ void nfs_init_commit(struct nfs_commit_data *data, struct list_head *head, struct pnfs_layout_segment *lseg, struct nfs_commit_info *cinfo) { struct nfs_page *first; struct nfs_open_context *ctx; struct inode *inode; /* Set up the RPC argument and reply structs * NB: take care not to mess about with data->commit et al. */ if (head) list_splice_init(head, &data->pages); first = nfs_list_entry(data->pages.next); ctx = nfs_req_openctx(first); inode = d_inode(ctx->dentry); data->inode = inode; data->cred = ctx->cred; data->lseg = lseg; /* reference transferred */ /* only set lwb for pnfs commit */ if (lseg) data->lwb = nfs_get_lwb(&data->pages); data->mds_ops = &nfs_commit_ops; data->completion_ops = cinfo->completion_ops; data->dreq = cinfo->dreq; data->args.fh = NFS_FH(data->inode); /* Note: we always request a commit of the entire inode */ data->args.offset = 0; data->args.count = 0; data->context = get_nfs_open_context(ctx); data->res.fattr = &data->fattr; data->res.verf = &data->verf; nfs_fattr_init(&data->fattr); nfs_commit_begin(cinfo->mds); } EXPORT_SYMBOL_GPL(nfs_init_commit); void nfs_retry_commit(struct list_head *page_list, struct pnfs_layout_segment *lseg, struct nfs_commit_info *cinfo, u32 ds_commit_idx) { struct nfs_page *req; while (!list_empty(page_list)) { req = nfs_list_entry(page_list->next); nfs_list_remove_request(req); nfs_mark_request_commit(req, lseg, cinfo, ds_commit_idx); nfs_folio_clear_commit(nfs_page_to_folio(req)); nfs_unlock_and_release_request(req); } } EXPORT_SYMBOL_GPL(nfs_retry_commit); static void nfs_commit_resched_write(struct nfs_commit_info *cinfo, struct nfs_page *req) { struct folio *folio = nfs_page_to_folio(req); filemap_dirty_folio(folio_mapping(folio), folio); } /* * Commit dirty pages */ static int nfs_commit_list(struct inode *inode, struct list_head *head, int how, struct nfs_commit_info *cinfo) { struct nfs_commit_data *data; struct nfsd_file *localio; unsigned short task_flags = 0; /* another commit raced with us */ if (list_empty(head)) return 0; data = nfs_commitdata_alloc(); if (!data) { nfs_retry_commit(head, NULL, cinfo, -1); return -ENOMEM; } /* Set up the argument struct */ nfs_init_commit(data, head, NULL, cinfo); if (NFS_SERVER(inode)->nfs_client->cl_minorversion) task_flags = RPC_TASK_MOVEABLE; localio = nfs_local_open_fh(NFS_SERVER(inode)->nfs_client, data->cred, data->args.fh, data->context->mode); return nfs_initiate_commit(NFS_CLIENT(inode), data, NFS_PROTO(inode), data->mds_ops, how, RPC_TASK_CRED_NOREF | task_flags, localio); } /* * COMMIT call returned */ static void nfs_commit_done(struct rpc_task *task, void *calldata) { struct nfs_commit_data *data = calldata; /* Call the NFS version-specific code */ NFS_PROTO(data->inode)->commit_done(task, data); trace_nfs_commit_done(task, data); } static void nfs_commit_release_pages(struct nfs_commit_data *data) { const struct nfs_writeverf *verf = data->res.verf; struct nfs_page *req; int status = data->task.tk_status; struct nfs_commit_info cinfo; struct folio *folio; while (!list_empty(&data->pages)) { req = nfs_list_entry(data->pages.next); nfs_list_remove_request(req); folio = nfs_page_to_folio(req); nfs_folio_clear_commit(folio); dprintk("NFS: commit (%s/%llu %d@%lld)", nfs_req_openctx(req)->dentry->d_sb->s_id, (unsigned long long)NFS_FILEID(d_inode(nfs_req_openctx(req)->dentry)), req->wb_bytes, (long long)req_offset(req)); if (status < 0) { if (folio) { trace_nfs_commit_error(data->inode, req, status); nfs_mapping_set_error(folio, status); nfs_inode_remove_request(req); } dprintk_cont(", error = %d\n", status); goto next; } /* Okay, COMMIT succeeded, apparently. Check the verifier * returned by the server against all stored verfs. */ if (nfs_write_match_verf(verf, req)) { /* We have a match */ if (folio) nfs_inode_remove_request(req); dprintk_cont(" OK\n"); goto next; } /* We have a mismatch. Write the page again */ dprintk_cont(" mismatch\n"); nfs_mark_request_dirty(req); atomic_long_inc(&NFS_I(data->inode)->redirtied_pages); next: nfs_unlock_and_release_request(req); /* Latency breaker */ cond_resched(); } nfs_init_cinfo(&cinfo, data->inode, data->dreq); nfs_commit_end(cinfo.mds); } static void nfs_commit_release(void *calldata) { struct nfs_commit_data *data = calldata; data->completion_ops->completion(data); nfs_commitdata_release(calldata); } static const struct rpc_call_ops nfs_commit_ops = { .rpc_call_prepare = nfs_commit_prepare, .rpc_call_done = nfs_commit_done, .rpc_release = nfs_commit_release, }; static const struct nfs_commit_completion_ops nfs_commit_completion_ops = { .completion = nfs_commit_release_pages, .resched_write = nfs_commit_resched_write, }; int nfs_generic_commit_list(struct inode *inode, struct list_head *head, int how, struct nfs_commit_info *cinfo) { int status; status = pnfs_commit_list(inode, head, how, cinfo); if (status == PNFS_NOT_ATTEMPTED) status = nfs_commit_list(inode, head, how, cinfo); return status; } static int __nfs_commit_inode(struct inode *inode, int how, struct writeback_control *wbc) { LIST_HEAD(head); struct nfs_commit_info cinfo; int may_wait = how & FLUSH_SYNC; int ret, nscan; how &= ~FLUSH_SYNC; nfs_init_cinfo_from_inode(&cinfo, inode); nfs_commit_begin(cinfo.mds); for (;;) { ret = nscan = nfs_scan_commit(inode, &head, &cinfo); if (ret <= 0) break; ret = nfs_generic_commit_list(inode, &head, how, &cinfo); if (ret < 0) break; ret = 0; if (wbc && wbc->sync_mode == WB_SYNC_NONE) { if (nscan < wbc->nr_to_write) wbc->nr_to_write -= nscan; else wbc->nr_to_write = 0; } if (nscan < INT_MAX) break; cond_resched(); } nfs_commit_end(cinfo.mds); if (ret || !may_wait) return ret; return wait_on_commit(cinfo.mds); } int nfs_commit_inode(struct inode *inode, int how) { return __nfs_commit_inode(inode, how, NULL); } EXPORT_SYMBOL_GPL(nfs_commit_inode); int nfs_write_inode(struct inode *inode, struct writeback_control *wbc) { struct nfs_inode *nfsi = NFS_I(inode); int flags = FLUSH_SYNC; int ret = 0; if (wbc->sync_mode == WB_SYNC_NONE) { /* no commits means nothing needs to be done */ if (!atomic_long_read(&nfsi->commit_info.ncommit)) goto check_requests_outstanding; /* Don't commit yet if this is a non-blocking flush and there * are a lot of outstanding writes for this mapping. */ if (mapping_tagged(inode->i_mapping, PAGECACHE_TAG_WRITEBACK)) goto out_mark_dirty; /* don't wait for the COMMIT response */ flags = 0; } ret = __nfs_commit_inode(inode, flags, wbc); if (!ret) { if (flags & FLUSH_SYNC) return 0; } else if (atomic_long_read(&nfsi->commit_info.ncommit)) goto out_mark_dirty; check_requests_outstanding: if (!atomic_read(&nfsi->commit_info.rpcs_out)) return ret; out_mark_dirty: __mark_inode_dirty(inode, I_DIRTY_DATASYNC); return ret; } EXPORT_SYMBOL_GPL(nfs_write_inode); /* * Wrapper for filemap_write_and_wait_range() * * Needed for pNFS in order to ensure data becomes visible to the * client. */ int nfs_filemap_write_and_wait_range(struct address_space *mapping, loff_t lstart, loff_t lend) { int ret; ret = filemap_write_and_wait_range(mapping, lstart, lend); if (ret == 0) ret = pnfs_sync_inode(mapping->host, true); return ret; } EXPORT_SYMBOL_GPL(nfs_filemap_write_and_wait_range); /* * flush the inode to disk. */ int nfs_wb_all(struct inode *inode) { int ret; trace_nfs_writeback_inode_enter(inode); ret = filemap_write_and_wait(inode->i_mapping); if (ret) goto out; ret = nfs_commit_inode(inode, FLUSH_SYNC); if (ret < 0) goto out; pnfs_sync_inode(inode, true); ret = 0; out: trace_nfs_writeback_inode_exit(inode, ret); return ret; } EXPORT_SYMBOL_GPL(nfs_wb_all); int nfs_wb_folio_cancel(struct inode *inode, struct folio *folio) { struct nfs_page *req; int ret = 0; folio_wait_writeback(folio); /* blocking call to cancel all requests and join to a single (head) * request */ req = nfs_lock_and_join_requests(folio); if (IS_ERR(req)) { ret = PTR_ERR(req); } else if (req) { /* all requests from this folio have been cancelled by * nfs_lock_and_join_requests, so just remove the head * request from the inode / page_private pointer and * release it */ nfs_inode_remove_request(req); nfs_unlock_and_release_request(req); } return ret; } /** * nfs_wb_folio - Write back all requests on one page * @inode: pointer to page * @folio: pointer to folio * * Assumes that the folio has been locked by the caller, and will * not unlock it. */ int nfs_wb_folio(struct inode *inode, struct folio *folio) { loff_t range_start = folio_pos(folio); size_t len = folio_size(folio); struct writeback_control wbc = { .sync_mode = WB_SYNC_ALL, .nr_to_write = 0, .range_start = range_start, .range_end = range_start + len - 1, }; int ret; trace_nfs_writeback_folio(inode, range_start, len); for (;;) { folio_wait_writeback(folio); if (folio_clear_dirty_for_io(folio)) { ret = nfs_writepage_locked(folio, &wbc); if (ret < 0) goto out_error; continue; } ret = 0; if (!folio_test_private(folio)) break; ret = nfs_commit_inode(inode, FLUSH_SYNC); if (ret < 0) goto out_error; } out_error: trace_nfs_writeback_folio_done(inode, range_start, len, ret); return ret; } #ifdef CONFIG_MIGRATION int nfs_migrate_folio(struct address_space *mapping, struct folio *dst, struct folio *src, enum migrate_mode mode) { /* * If the private flag is set, the folio is currently associated with * an in-progress read or write request. Don't try to migrate it. * * FIXME: we could do this in principle, but we'll need a way to ensure * that we can safely release the inode reference while holding * the folio lock. */ if (folio_test_private(src)) return -EBUSY; if (folio_test_private_2(src)) { /* [DEPRECATED] */ if (mode == MIGRATE_ASYNC) return -EBUSY; folio_wait_private_2(src); } return migrate_folio(mapping, dst, src, mode); } #endif int __init nfs_init_writepagecache(void) { nfs_wdata_cachep = kmem_cache_create("nfs_write_data", sizeof(struct nfs_pgio_header), 0, SLAB_HWCACHE_ALIGN, NULL); if (nfs_wdata_cachep == NULL) return -ENOMEM; nfs_wdata_mempool = mempool_create_slab_pool(MIN_POOL_WRITE, nfs_wdata_cachep); if (nfs_wdata_mempool == NULL) goto out_destroy_write_cache; nfs_cdata_cachep = kmem_cache_create("nfs_commit_data", sizeof(struct nfs_commit_data), 0, SLAB_HWCACHE_ALIGN, NULL); if (nfs_cdata_cachep == NULL) goto out_destroy_write_mempool; nfs_commit_mempool = mempool_create_slab_pool(MIN_POOL_COMMIT, nfs_cdata_cachep); if (nfs_commit_mempool == NULL) goto out_destroy_commit_cache; /* * NFS congestion size, scale with available memory. * * 64MB: 8192k * 128MB: 11585k * 256MB: 16384k * 512MB: 23170k * 1GB: 32768k * 2GB: 46340k * 4GB: 65536k * 8GB: 92681k * 16GB: 131072k * * This allows larger machines to have larger/more transfers. * Limit the default to 256M */ nfs_congestion_kb = (16*int_sqrt(totalram_pages())) << (PAGE_SHIFT-10); if (nfs_congestion_kb > 256*1024) nfs_congestion_kb = 256*1024; return 0; out_destroy_commit_cache: kmem_cache_destroy(nfs_cdata_cachep); out_destroy_write_mempool: mempool_destroy(nfs_wdata_mempool); out_destroy_write_cache: kmem_cache_destroy(nfs_wdata_cachep); return -ENOMEM; } void nfs_destroy_writepagecache(void) { mempool_destroy(nfs_commit_mempool); kmem_cache_destroy(nfs_cdata_cachep); mempool_destroy(nfs_wdata_mempool); kmem_cache_destroy(nfs_wdata_cachep); } static const struct nfs_rw_ops nfs_rw_write_ops = { .rw_alloc_header = nfs_writehdr_alloc, .rw_free_header = nfs_writehdr_free, .rw_done = nfs_writeback_done, .rw_result = nfs_writeback_result, .rw_initiate = nfs_initiate_write, };