/* * linux/fs/nfs/write.c * * Write file data over NFS. * * Copyright (C) 1996, 1997, Olaf Kirch <okir@monad.swb.de> */ #include <linux/types.h> #include <linux/slab.h> #include <linux/mm.h> #include <linux/pagemap.h> #include <linux/file.h> #include <linux/writeback.h> #include <linux/swap.h> #include <linux/sunrpc/clnt.h> #include <linux/nfs_fs.h> #include <linux/nfs_mount.h> #include <linux/nfs_page.h> #include <linux/backing-dev.h> #include <asm/uaccess.h> #include "delegation.h" #include "internal.h" #include "iostat.h" #define NFSDBG_FACILITY NFSDBG_PAGECACHE #define MIN_POOL_WRITE (32) #define MIN_POOL_COMMIT (4) /* * Local function declarations */ static void nfs_pageio_init_write(struct nfs_pageio_descriptor *desc, struct inode *inode, int ioflags); static void nfs_redirty_request(struct nfs_page *req); static const struct rpc_call_ops nfs_write_partial_ops; static const struct rpc_call_ops nfs_write_full_ops; static const struct rpc_call_ops nfs_commit_ops; static struct kmem_cache *nfs_wdata_cachep; static mempool_t *nfs_wdata_mempool; static mempool_t *nfs_commit_mempool; struct nfs_write_data *nfs_commitdata_alloc(void) { struct nfs_write_data *p = mempool_alloc(nfs_commit_mempool, GFP_NOFS); if (p) { memset(p, 0, sizeof(*p)); INIT_LIST_HEAD(&p->pages); } return p; } void nfs_commit_free(struct nfs_write_data *p) { if (p && (p->pagevec != &p->page_array[0])) kfree(p->pagevec); mempool_free(p, nfs_commit_mempool); } struct nfs_write_data *nfs_writedata_alloc(unsigned int pagecount) { struct nfs_write_data *p = mempool_alloc(nfs_wdata_mempool, GFP_NOFS); if (p) { memset(p, 0, sizeof(*p)); INIT_LIST_HEAD(&p->pages); p->npages = pagecount; if (pagecount <= ARRAY_SIZE(p->page_array)) p->pagevec = p->page_array; else { p->pagevec = kcalloc(pagecount, sizeof(struct page *), GFP_NOFS); if (!p->pagevec) { mempool_free(p, nfs_wdata_mempool); p = NULL; } } } return p; } static void nfs_writedata_free(struct nfs_write_data *p) { if (p && (p->pagevec != &p->page_array[0])) kfree(p->pagevec); mempool_free(p, nfs_wdata_mempool); } void nfs_writedata_release(void *data) { struct nfs_write_data *wdata = data; put_nfs_open_context(wdata->args.context); nfs_writedata_free(wdata); } static void nfs_context_set_write_error(struct nfs_open_context *ctx, int error) { ctx->error = error; smp_wmb(); set_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags); } static struct nfs_page *nfs_page_find_request_locked(struct page *page) { struct nfs_page *req = NULL; if (PagePrivate(page)) { req = (struct nfs_page *)page_private(page); if (req != NULL) kref_get(&req->wb_kref); } return req; } static struct nfs_page *nfs_page_find_request(struct page *page) { struct inode *inode = page->mapping->host; struct nfs_page *req = NULL; spin_lock(&inode->i_lock); req = nfs_page_find_request_locked(page); spin_unlock(&inode->i_lock); return req; } /* Adjust the file length if we're writing beyond the end */ static void nfs_grow_file(struct page *page, unsigned int offset, unsigned int count) { struct inode *inode = page->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) >> PAGE_CACHE_SHIFT; if (i_size > 0 && page->index < end_index) goto out; end = ((loff_t)page->index << PAGE_CACHE_SHIFT) + ((loff_t)offset+count); if (i_size >= end) goto out; i_size_write(inode, end); nfs_inc_stats(inode, NFSIOS_EXTENDWRITE); out: spin_unlock(&inode->i_lock); } /* A writeback failed: mark the page as bad, and invalidate the page cache */ static void nfs_set_pageerror(struct page *page) { SetPageError(page); nfs_zap_mapping(page->mapping->host, page->mapping); } /* We can set the PG_uptodate flag if we see that a write request * covers the full page. */ static void nfs_mark_uptodate(struct page *page, unsigned int base, unsigned int count) { if (PageUptodate(page)) return; if (base != 0) return; if (count != nfs_page_length(page)) return; SetPageUptodate(page); } static int wb_priority(struct writeback_control *wbc) { if (wbc->for_reclaim) return FLUSH_HIGHPRI | FLUSH_STABLE; if (wbc->for_kupdate) return FLUSH_LOWPRI; return 0; } /* * 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 int nfs_set_page_writeback(struct page *page) { int ret = test_set_page_writeback(page); if (!ret) { struct inode *inode = page->mapping->host; struct nfs_server *nfss = NFS_SERVER(inode); if (atomic_long_inc_return(&nfss->writeback) > NFS_CONGESTION_ON_THRESH) set_bdi_congested(&nfss->backing_dev_info, WRITE); } return ret; } static void nfs_end_page_writeback(struct page *page) { struct inode *inode = page->mapping->host; struct nfs_server *nfss = NFS_SERVER(inode); end_page_writeback(page); if (atomic_long_dec_return(&nfss->writeback) < NFS_CONGESTION_OFF_THRESH) clear_bdi_congested(&nfss->backing_dev_info, WRITE); } /* * 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 nfs_pageio_descriptor *pgio, struct page *page) { struct inode *inode = page->mapping->host; struct nfs_page *req; int ret; spin_lock(&inode->i_lock); for(;;) { req = nfs_page_find_request_locked(page); if (req == NULL) { spin_unlock(&inode->i_lock); return 0; } if (nfs_set_page_tag_locked(req)) break; /* Note: If we hold the page lock, as is the case in nfs_writepage, * then the call to nfs_set_page_tag_locked() will always * succeed provided that someone hasn't already marked the * request as dirty (in which case we don't care). */ spin_unlock(&inode->i_lock); ret = nfs_wait_on_request(req); nfs_release_request(req); if (ret != 0) return ret; spin_lock(&inode->i_lock); } if (test_bit(PG_CLEAN, &req->wb_flags)) { spin_unlock(&inode->i_lock); BUG(); } if (nfs_set_page_writeback(page) != 0) { spin_unlock(&inode->i_lock); BUG(); } spin_unlock(&inode->i_lock); if (!nfs_pageio_add_request(pgio, req)) { nfs_redirty_request(req); return pgio->pg_error; } return 0; } static int nfs_do_writepage(struct page *page, struct writeback_control *wbc, struct nfs_pageio_descriptor *pgio) { struct inode *inode = page->mapping->host; nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGE); nfs_add_stats(inode, NFSIOS_WRITEPAGES, 1); nfs_pageio_cond_complete(pgio, page->index); return nfs_page_async_flush(pgio, page); } /* * Write an mmapped page to the server. */ static int nfs_writepage_locked(struct page *page, struct writeback_control *wbc) { struct nfs_pageio_descriptor pgio; int err; nfs_pageio_init_write(&pgio, page->mapping->host, wb_priority(wbc)); err = nfs_do_writepage(page, wbc, &pgio); nfs_pageio_complete(&pgio); if (err < 0) return err; if (pgio.pg_error < 0) return pgio.pg_error; return 0; } int nfs_writepage(struct page *page, struct writeback_control *wbc) { int ret; ret = nfs_writepage_locked(page, wbc); unlock_page(page); return ret; } static int nfs_writepages_callback(struct page *page, struct writeback_control *wbc, void *data) { int ret; ret = nfs_do_writepage(page, wbc, data); unlock_page(page); return ret; } int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc) { struct inode *inode = mapping->host; struct nfs_pageio_descriptor pgio; int err; nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGES); nfs_pageio_init_write(&pgio, inode, wb_priority(wbc)); err = write_cache_pages(mapping, wbc, nfs_writepages_callback, &pgio); nfs_pageio_complete(&pgio); if (err < 0) return err; if (pgio.pg_error < 0) return pgio.pg_error; return 0; } /* * Insert a write request into an inode */ static int nfs_inode_add_request(struct inode *inode, struct nfs_page *req) { struct nfs_inode *nfsi = NFS_I(inode); int error; error = radix_tree_preload(GFP_NOFS); if (error != 0) goto out; /* Lock the request! */ nfs_lock_request_dontget(req); spin_lock(&inode->i_lock); error = radix_tree_insert(&nfsi->nfs_page_tree, req->wb_index, req); BUG_ON(error); if (!nfsi->npages) { igrab(inode); if (nfs_have_delegation(inode, FMODE_WRITE)) nfsi->change_attr++; } SetPagePrivate(req->wb_page); set_page_private(req->wb_page, (unsigned long)req); nfsi->npages++; kref_get(&req->wb_kref); radix_tree_tag_set(&nfsi->nfs_page_tree, req->wb_index, NFS_PAGE_TAG_LOCKED); spin_unlock(&inode->i_lock); radix_tree_preload_end(); out: return error; } /* * Remove a write request from an inode */ static void nfs_inode_remove_request(struct nfs_page *req) { struct inode *inode = req->wb_context->path.dentry->d_inode; struct nfs_inode *nfsi = NFS_I(inode); BUG_ON (!NFS_WBACK_BUSY(req)); spin_lock(&inode->i_lock); set_page_private(req->wb_page, 0); ClearPagePrivate(req->wb_page); radix_tree_delete(&nfsi->nfs_page_tree, req->wb_index); nfsi->npages--; if (!nfsi->npages) { spin_unlock(&inode->i_lock); iput(inode); } else spin_unlock(&inode->i_lock); nfs_clear_request(req); nfs_release_request(req); } static void nfs_mark_request_dirty(struct nfs_page *req) { __set_page_dirty_nobuffers(req->wb_page); } #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4) /* * Add a request to the inode's commit list. */ static void nfs_mark_request_commit(struct nfs_page *req) { struct inode *inode = req->wb_context->path.dentry->d_inode; struct nfs_inode *nfsi = NFS_I(inode); spin_lock(&inode->i_lock); nfsi->ncommit++; set_bit(PG_CLEAN, &(req)->wb_flags); radix_tree_tag_set(&nfsi->nfs_page_tree, req->wb_index, NFS_PAGE_TAG_COMMIT); spin_unlock(&inode->i_lock); inc_zone_page_state(req->wb_page, NR_UNSTABLE_NFS); inc_bdi_stat(req->wb_page->mapping->backing_dev_info, BDI_RECLAIMABLE); __mark_inode_dirty(inode, I_DIRTY_DATASYNC); } static int nfs_clear_request_commit(struct nfs_page *req) { struct page *page = req->wb_page; if (test_and_clear_bit(PG_CLEAN, &(req)->wb_flags)) { dec_zone_page_state(page, NR_UNSTABLE_NFS); dec_bdi_stat(page->mapping->backing_dev_info, BDI_RECLAIMABLE); return 1; } return 0; } static inline int nfs_write_need_commit(struct nfs_write_data *data) { return data->verf.committed != NFS_FILE_SYNC; } static inline int nfs_reschedule_unstable_write(struct nfs_page *req) { if (test_and_clear_bit(PG_NEED_COMMIT, &req->wb_flags)) { nfs_mark_request_commit(req); return 1; } if (test_and_clear_bit(PG_NEED_RESCHED, &req->wb_flags)) { nfs_mark_request_dirty(req); return 1; } return 0; } #else static inline void nfs_mark_request_commit(struct nfs_page *req) { } static inline int nfs_clear_request_commit(struct nfs_page *req) { return 0; } static inline int nfs_write_need_commit(struct nfs_write_data *data) { return 0; } static inline int nfs_reschedule_unstable_write(struct nfs_page *req) { return 0; } #endif /* * Wait for a request to complete. * * Interruptible by fatal signals only. */ static int nfs_wait_on_requests_locked(struct inode *inode, pgoff_t idx_start, unsigned int npages) { struct nfs_inode *nfsi = NFS_I(inode); struct nfs_page *req; pgoff_t idx_end, next; unsigned int res = 0; int error; if (npages == 0) idx_end = ~0; else idx_end = idx_start + npages - 1; next = idx_start; while (radix_tree_gang_lookup_tag(&nfsi->nfs_page_tree, (void **)&req, next, 1, NFS_PAGE_TAG_LOCKED)) { if (req->wb_index > idx_end) break; next = req->wb_index + 1; BUG_ON(!NFS_WBACK_BUSY(req)); kref_get(&req->wb_kref); spin_unlock(&inode->i_lock); error = nfs_wait_on_request(req); nfs_release_request(req); spin_lock(&inode->i_lock); if (error < 0) return error; res++; } return res; } static void nfs_cancel_commit_list(struct list_head *head) { struct nfs_page *req; while(!list_empty(head)) { req = nfs_list_entry(head->next); nfs_list_remove_request(req); nfs_clear_request_commit(req); nfs_inode_remove_request(req); nfs_unlock_request(req); } } #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4) /* * nfs_scan_commit - Scan an inode for commit requests * @inode: NFS inode to scan * @dst: destination list * @idx_start: lower bound of page->index to scan. * @npages: idx_start + npages sets the upper bound to scan. * * Moves requests from the inode's 'commit' request list. * The requests are *not* checked to ensure that they form a contiguous set. */ static int nfs_scan_commit(struct inode *inode, struct list_head *dst, pgoff_t idx_start, unsigned int npages) { struct nfs_inode *nfsi = NFS_I(inode); int res = 0; if (nfsi->ncommit != 0) { res = nfs_scan_list(nfsi, dst, idx_start, npages, NFS_PAGE_TAG_COMMIT); nfsi->ncommit -= res; } return res; } #else static inline int nfs_scan_commit(struct inode *inode, struct list_head *dst, pgoff_t idx_start, unsigned int npages) { return 0; } #endif /* * 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 inode *inode, struct page *page, unsigned int offset, unsigned int bytes) { struct nfs_page *req; unsigned int rqend; unsigned int end; int error; if (!PagePrivate(page)) return NULL; end = offset + bytes; spin_lock(&inode->i_lock); for (;;) { req = nfs_page_find_request_locked(page); if (req == NULL) goto out_unlock; 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; if (nfs_set_page_tag_locked(req)) break; /* The request is locked, so wait and then retry */ spin_unlock(&inode->i_lock); error = nfs_wait_on_request(req); nfs_release_request(req); if (error != 0) goto out_err; spin_lock(&inode->i_lock); } if (nfs_clear_request_commit(req)) radix_tree_tag_clear(&NFS_I(inode)->nfs_page_tree, req->wb_index, NFS_PAGE_TAG_COMMIT); /* 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; out_unlock: spin_unlock(&inode->i_lock); return req; out_flushme: spin_unlock(&inode->i_lock); nfs_release_request(req); error = nfs_wb_page(inode, page); out_err: return ERR_PTR(error); } /* * 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 page *page, unsigned int offset, unsigned int bytes) { struct inode *inode = page->mapping->host; struct nfs_page *req; int error; req = nfs_try_to_update_request(inode, page, offset, bytes); if (req != NULL) goto out; req = nfs_create_request(ctx, inode, page, offset, bytes); if (IS_ERR(req)) goto out; error = nfs_inode_add_request(inode, req); if (error != 0) { nfs_release_request(req); req = ERR_PTR(error); } out: return req; } static int nfs_writepage_setup(struct nfs_open_context *ctx, struct page *page, unsigned int offset, unsigned int count) { struct nfs_page *req; req = nfs_setup_write_request(ctx, page, offset, count); if (IS_ERR(req)) return PTR_ERR(req); /* Update file length */ nfs_grow_file(page, offset, count); nfs_mark_uptodate(page, req->wb_pgbase, req->wb_bytes); nfs_clear_page_tag_locked(req); return 0; } int nfs_flush_incompatible(struct file *file, struct page *page) { struct nfs_open_context *ctx = nfs_file_open_context(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_page_find_request(page); if (req == NULL) return 0; do_flush = req->wb_page != page || req->wb_context != ctx; nfs_release_request(req); if (!do_flush) return 0; status = nfs_wb_page(page->mapping->host, page); } while (status == 0); return status; } /* * 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 int nfs_write_pageuptodate(struct page *page, struct inode *inode) { return PageUptodate(page) && !(NFS_I(inode)->cache_validity & (NFS_INO_REVAL_PAGECACHE|NFS_INO_INVALID_DATA)); } /* * 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_updatepage(struct file *file, struct page *page, unsigned int offset, unsigned int count) { struct nfs_open_context *ctx = nfs_file_open_context(file); struct inode *inode = page->mapping->host; int status = 0; nfs_inc_stats(inode, NFSIOS_VFSUPDATEPAGE); dprintk("NFS: nfs_updatepage(%s/%s %d@%lld)\n", file->f_path.dentry->d_parent->d_name.name, file->f_path.dentry->d_name.name, count, (long long)(page_offset(page) + offset)); /* If we're not using byte range locks, and we know the page * is up to date, it may be more efficient to extend the write * to cover the entire page in order to avoid fragmentation * inefficiencies. */ if (nfs_write_pageuptodate(page, inode) && inode->i_flock == NULL && !(file->f_flags & O_SYNC)) { count = max(count + offset, nfs_page_length(page)); offset = 0; } status = nfs_writepage_setup(ctx, page, offset, count); if (status < 0) nfs_set_pageerror(page); else __set_page_dirty_nobuffers(page); dprintk("NFS: nfs_updatepage returns %d (isize %lld)\n", status, (long long)i_size_read(inode)); return status; } static void nfs_writepage_release(struct nfs_page *req) { if (PageError(req->wb_page) || !nfs_reschedule_unstable_write(req)) { nfs_end_page_writeback(req->wb_page); nfs_inode_remove_request(req); } else nfs_end_page_writeback(req->wb_page); nfs_clear_page_tag_locked(req); } 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; } /* * Set up the argument/result storage required for the RPC call. */ static int nfs_write_rpcsetup(struct nfs_page *req, struct nfs_write_data *data, const struct rpc_call_ops *call_ops, unsigned int count, unsigned int offset, int how) { struct inode *inode = req->wb_context->path.dentry->d_inode; int flags = (how & FLUSH_SYNC) ? 0 : RPC_TASK_ASYNC; int priority = flush_task_priority(how); struct rpc_task *task; struct rpc_message msg = { .rpc_argp = &data->args, .rpc_resp = &data->res, .rpc_cred = req->wb_context->cred, }; struct rpc_task_setup task_setup_data = { .rpc_client = NFS_CLIENT(inode), .task = &data->task, .rpc_message = &msg, .callback_ops = call_ops, .callback_data = data, .workqueue = nfsiod_workqueue, .flags = flags, .priority = priority, }; /* Set up the RPC argument and reply structs * NB: take care not to mess about with data->commit et al. */ data->req = req; data->inode = inode = req->wb_context->path.dentry->d_inode; data->cred = msg.rpc_cred; data->args.fh = NFS_FH(inode); data->args.offset = req_offset(req) + offset; data->args.pgbase = req->wb_pgbase + offset; data->args.pages = data->pagevec; data->args.count = count; data->args.context = get_nfs_open_context(req->wb_context); data->args.stable = NFS_UNSTABLE; if (how & FLUSH_STABLE) { data->args.stable = NFS_DATA_SYNC; if (!NFS_I(inode)->ncommit) data->args.stable = NFS_FILE_SYNC; } data->res.fattr = &data->fattr; data->res.count = count; data->res.verf = &data->verf; nfs_fattr_init(&data->fattr); /* Set up the initial task struct. */ NFS_PROTO(inode)->write_setup(data, &msg); dprintk("NFS: %5u initiated write call " "(req %s/%lld, %u bytes @ offset %llu)\n", data->task.tk_pid, inode->i_sb->s_id, (long long)NFS_FILEID(inode), count, (unsigned long long)data->args.offset); task = rpc_run_task(&task_setup_data); if (IS_ERR(task)) return PTR_ERR(task); rpc_put_task(task); return 0; } /* 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) { nfs_mark_request_dirty(req); nfs_end_page_writeback(req->wb_page); nfs_clear_page_tag_locked(req); } /* * Generate multiple small requests to write out a single * contiguous dirty area on one page. */ static int nfs_flush_multi(struct inode *inode, struct list_head *head, unsigned int npages, size_t count, int how) { struct nfs_page *req = nfs_list_entry(head->next); struct page *page = req->wb_page; struct nfs_write_data *data; size_t wsize = NFS_SERVER(inode)->wsize, nbytes; unsigned int offset; int requests = 0; int ret = 0; LIST_HEAD(list); nfs_list_remove_request(req); nbytes = count; do { size_t len = min(nbytes, wsize); data = nfs_writedata_alloc(1); if (!data) goto out_bad; list_add(&data->pages, &list); requests++; nbytes -= len; } while (nbytes != 0); atomic_set(&req->wb_complete, requests); ClearPageError(page); offset = 0; nbytes = count; do { int ret2; data = list_entry(list.next, struct nfs_write_data, pages); list_del_init(&data->pages); data->pagevec[0] = page; if (nbytes < wsize) wsize = nbytes; ret2 = nfs_write_rpcsetup(req, data, &nfs_write_partial_ops, wsize, offset, how); if (ret == 0) ret = ret2; offset += wsize; nbytes -= wsize; } while (nbytes != 0); return ret; out_bad: while (!list_empty(&list)) { data = list_entry(list.next, struct nfs_write_data, pages); list_del(&data->pages); nfs_writedata_release(data); } nfs_redirty_request(req); return -ENOMEM; } /* * Create an RPC task for the given write request and kick it. * The page must have been locked by the caller. * * It may happen that the page we're passed is not marked dirty. * This is the case if nfs_updatepage detects a conflicting request * that has been written but not committed. */ static int nfs_flush_one(struct inode *inode, struct list_head *head, unsigned int npages, size_t count, int how) { struct nfs_page *req; struct page **pages; struct nfs_write_data *data; data = nfs_writedata_alloc(npages); if (!data) goto out_bad; pages = data->pagevec; while (!list_empty(head)) { req = nfs_list_entry(head->next); nfs_list_remove_request(req); nfs_list_add_request(req, &data->pages); ClearPageError(req->wb_page); *pages++ = req->wb_page; } req = nfs_list_entry(data->pages.next); /* Set up the argument struct */ return nfs_write_rpcsetup(req, data, &nfs_write_full_ops, count, 0, how); out_bad: while (!list_empty(head)) { req = nfs_list_entry(head->next); nfs_list_remove_request(req); nfs_redirty_request(req); } return -ENOMEM; } static void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio, struct inode *inode, int ioflags) { size_t wsize = NFS_SERVER(inode)->wsize; if (wsize < PAGE_CACHE_SIZE) nfs_pageio_init(pgio, inode, nfs_flush_multi, wsize, ioflags); else nfs_pageio_init(pgio, inode, nfs_flush_one, wsize, ioflags); } /* * Handle a write reply that flushed part of a page. */ static void nfs_writeback_done_partial(struct rpc_task *task, void *calldata) { struct nfs_write_data *data = calldata; dprintk("NFS: %5u write(%s/%lld %d@%lld)", task->tk_pid, data->req->wb_context->path.dentry->d_inode->i_sb->s_id, (long long) NFS_FILEID(data->req->wb_context->path.dentry->d_inode), data->req->wb_bytes, (long long)req_offset(data->req)); nfs_writeback_done(task, data); } static void nfs_writeback_release_partial(void *calldata) { struct nfs_write_data *data = calldata; struct nfs_page *req = data->req; struct page *page = req->wb_page; int status = data->task.tk_status; if (status < 0) { nfs_set_pageerror(page); nfs_context_set_write_error(req->wb_context, status); dprintk(", error = %d\n", status); goto out; } if (nfs_write_need_commit(data)) { struct inode *inode = page->mapping->host; spin_lock(&inode->i_lock); if (test_bit(PG_NEED_RESCHED, &req->wb_flags)) { /* Do nothing we need to resend the writes */ } else if (!test_and_set_bit(PG_NEED_COMMIT, &req->wb_flags)) { memcpy(&req->wb_verf, &data->verf, sizeof(req->wb_verf)); dprintk(" defer commit\n"); } else if (memcmp(&req->wb_verf, &data->verf, sizeof(req->wb_verf))) { set_bit(PG_NEED_RESCHED, &req->wb_flags); clear_bit(PG_NEED_COMMIT, &req->wb_flags); dprintk(" server reboot detected\n"); } spin_unlock(&inode->i_lock); } else dprintk(" OK\n"); out: if (atomic_dec_and_test(&req->wb_complete)) nfs_writepage_release(req); nfs_writedata_release(calldata); } static const struct rpc_call_ops nfs_write_partial_ops = { .rpc_call_done = nfs_writeback_done_partial, .rpc_release = nfs_writeback_release_partial, }; /* * Handle a write reply that flushes a whole page. * * FIXME: There is an inherent race with invalidate_inode_pages and * writebacks since the page->count is kept > 1 for as long * as the page has a write request pending. */ static void nfs_writeback_done_full(struct rpc_task *task, void *calldata) { struct nfs_write_data *data = calldata; nfs_writeback_done(task, data); } static void nfs_writeback_release_full(void *calldata) { struct nfs_write_data *data = calldata; int status = data->task.tk_status; /* Update attributes as result of writeback. */ while (!list_empty(&data->pages)) { struct nfs_page *req = nfs_list_entry(data->pages.next); struct page *page = req->wb_page; nfs_list_remove_request(req); dprintk("NFS: %5u write (%s/%lld %d@%lld)", data->task.tk_pid, req->wb_context->path.dentry->d_inode->i_sb->s_id, (long long)NFS_FILEID(req->wb_context->path.dentry->d_inode), req->wb_bytes, (long long)req_offset(req)); if (status < 0) { nfs_set_pageerror(page); nfs_context_set_write_error(req->wb_context, status); dprintk(", error = %d\n", status); goto remove_request; } if (nfs_write_need_commit(data)) { memcpy(&req->wb_verf, &data->verf, sizeof(req->wb_verf)); nfs_mark_request_commit(req); nfs_end_page_writeback(page); dprintk(" marked for commit\n"); goto next; } dprintk(" OK\n"); remove_request: nfs_end_page_writeback(page); nfs_inode_remove_request(req); next: nfs_clear_page_tag_locked(req); } nfs_writedata_release(calldata); } static const struct rpc_call_ops nfs_write_full_ops = { .rpc_call_done = nfs_writeback_done_full, .rpc_release = nfs_writeback_release_full, }; /* * This function is called when the WRITE call is complete. */ int nfs_writeback_done(struct rpc_task *task, struct nfs_write_data *data) { struct nfs_writeargs *argp = &data->args; struct nfs_writeres *resp = &data->res; int status; dprintk("NFS: %5u nfs_writeback_done (status %d)\n", task->tk_pid, task->tk_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(data->inode)->write_done(task, data); if (status != 0) return status; nfs_add_stats(data->inode, NFSIOS_SERVERWRITTENBYTES, resp->count); #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4) if (resp->verf->committed < argp->stable && task->tk_status >= 0) { /* 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; if (time_before(complain, jiffies)) { dprintk("NFS: faulty NFS server %s:" " (committed = %d) != (stable = %d)\n", NFS_SERVER(data->inode)->nfs_client->cl_hostname, resp->verf->committed, argp->stable); complain = jiffies + 300 * HZ; } } #endif /* Is this a short write? */ if (task->tk_status >= 0 && resp->count < argp->count) { static unsigned long complain; nfs_inc_stats(data->inode, NFSIOS_SHORTWRITE); /* Has the server at least made some progress? */ if (resp->count != 0) { /* Was this an NFSv2 write or an NFSv3 stable write? */ if (resp->verf->committed != NFS_UNSTABLE) { /* Resend from where the server left off */ 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; } rpc_restart_call(task); return -EAGAIN; } if (time_before(complain, jiffies)) { printk(KERN_WARNING "NFS: Server wrote zero bytes, expected %u.\n", argp->count); complain = jiffies + 300 * HZ; } /* Can't do anything about it except throw an error. */ task->tk_status = -EIO; } return 0; } #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4) void nfs_commitdata_release(void *data) { struct nfs_write_data *wdata = data; put_nfs_open_context(wdata->args.context); nfs_commit_free(wdata); } /* * Set up the argument/result storage required for the RPC call. */ static int nfs_commit_rpcsetup(struct list_head *head, struct nfs_write_data *data, int how) { struct nfs_page *first = nfs_list_entry(head->next); struct inode *inode = first->wb_context->path.dentry->d_inode; int flags = (how & FLUSH_SYNC) ? 0 : RPC_TASK_ASYNC; int priority = flush_task_priority(how); struct rpc_task *task; struct rpc_message msg = { .rpc_argp = &data->args, .rpc_resp = &data->res, .rpc_cred = first->wb_context->cred, }; struct rpc_task_setup task_setup_data = { .task = &data->task, .rpc_client = NFS_CLIENT(inode), .rpc_message = &msg, .callback_ops = &nfs_commit_ops, .callback_data = data, .workqueue = nfsiod_workqueue, .flags = flags, .priority = priority, }; /* Set up the RPC argument and reply structs * NB: take care not to mess about with data->commit et al. */ list_splice_init(head, &data->pages); data->inode = inode; data->cred = msg.rpc_cred; 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->args.context = get_nfs_open_context(first->wb_context); data->res.count = 0; data->res.fattr = &data->fattr; data->res.verf = &data->verf; nfs_fattr_init(&data->fattr); /* Set up the initial task struct. */ NFS_PROTO(inode)->commit_setup(data, &msg); dprintk("NFS: %5u initiated commit call\n", data->task.tk_pid); task = rpc_run_task(&task_setup_data); if (IS_ERR(task)) return PTR_ERR(task); rpc_put_task(task); return 0; } /* * Commit dirty pages */ static int nfs_commit_list(struct inode *inode, struct list_head *head, int how) { struct nfs_write_data *data; struct nfs_page *req; data = nfs_commitdata_alloc(); if (!data) goto out_bad; /* Set up the argument struct */ return nfs_commit_rpcsetup(head, data, how); out_bad: while (!list_empty(head)) { req = nfs_list_entry(head->next); nfs_list_remove_request(req); nfs_mark_request_commit(req); dec_zone_page_state(req->wb_page, NR_UNSTABLE_NFS); dec_bdi_stat(req->wb_page->mapping->backing_dev_info, BDI_RECLAIMABLE); nfs_clear_page_tag_locked(req); } return -ENOMEM; } /* * COMMIT call returned */ static void nfs_commit_done(struct rpc_task *task, void *calldata) { struct nfs_write_data *data = calldata; dprintk("NFS: %5u nfs_commit_done (status %d)\n", task->tk_pid, task->tk_status); /* Call the NFS version-specific code */ if (NFS_PROTO(data->inode)->commit_done(task, data) != 0) return; } static void nfs_commit_release(void *calldata) { struct nfs_write_data *data = calldata; struct nfs_page *req; int status = data->task.tk_status; while (!list_empty(&data->pages)) { req = nfs_list_entry(data->pages.next); nfs_list_remove_request(req); nfs_clear_request_commit(req); dprintk("NFS: commit (%s/%lld %d@%lld)", req->wb_context->path.dentry->d_inode->i_sb->s_id, (long long)NFS_FILEID(req->wb_context->path.dentry->d_inode), req->wb_bytes, (long long)req_offset(req)); if (status < 0) { nfs_context_set_write_error(req->wb_context, status); nfs_inode_remove_request(req); dprintk(", error = %d\n", status); goto next; } /* Okay, COMMIT succeeded, apparently. Check the verifier * returned by the server against all stored verfs. */ if (!memcmp(req->wb_verf.verifier, data->verf.verifier, sizeof(data->verf.verifier))) { /* We have a match */ nfs_inode_remove_request(req); dprintk(" OK\n"); goto next; } /* We have a mismatch. Write the page again */ dprintk(" mismatch\n"); nfs_mark_request_dirty(req); next: nfs_clear_page_tag_locked(req); } nfs_commitdata_release(calldata); } static const struct rpc_call_ops nfs_commit_ops = { .rpc_call_done = nfs_commit_done, .rpc_release = nfs_commit_release, }; int nfs_commit_inode(struct inode *inode, int how) { LIST_HEAD(head); int res; spin_lock(&inode->i_lock); res = nfs_scan_commit(inode, &head, 0, 0); spin_unlock(&inode->i_lock); if (res) { int error = nfs_commit_list(inode, &head, how); if (error < 0) return error; } return res; } #else static inline int nfs_commit_list(struct inode *inode, struct list_head *head, int how) { return 0; } #endif long nfs_sync_mapping_wait(struct address_space *mapping, struct writeback_control *wbc, int how) { struct inode *inode = mapping->host; pgoff_t idx_start, idx_end; unsigned int npages = 0; LIST_HEAD(head); int nocommit = how & FLUSH_NOCOMMIT; long pages, ret; /* FIXME */ if (wbc->range_cyclic) idx_start = 0; else { idx_start = wbc->range_start >> PAGE_CACHE_SHIFT; idx_end = wbc->range_end >> PAGE_CACHE_SHIFT; if (idx_end > idx_start) { pgoff_t l_npages = 1 + idx_end - idx_start; npages = l_npages; if (sizeof(npages) != sizeof(l_npages) && (pgoff_t)npages != l_npages) npages = 0; } } how &= ~FLUSH_NOCOMMIT; spin_lock(&inode->i_lock); do { ret = nfs_wait_on_requests_locked(inode, idx_start, npages); if (ret != 0) continue; if (nocommit) break; pages = nfs_scan_commit(inode, &head, idx_start, npages); if (pages == 0) break; if (how & FLUSH_INVALIDATE) { spin_unlock(&inode->i_lock); nfs_cancel_commit_list(&head); ret = pages; spin_lock(&inode->i_lock); continue; } pages += nfs_scan_commit(inode, &head, 0, 0); spin_unlock(&inode->i_lock); ret = nfs_commit_list(inode, &head, how); spin_lock(&inode->i_lock); } while (ret >= 0); spin_unlock(&inode->i_lock); return ret; } static int __nfs_write_mapping(struct address_space *mapping, struct writeback_control *wbc, int how) { int ret; ret = nfs_writepages(mapping, wbc); if (ret < 0) goto out; ret = nfs_sync_mapping_wait(mapping, wbc, how); if (ret < 0) goto out; return 0; out: __mark_inode_dirty(mapping->host, I_DIRTY_PAGES); return ret; } /* Two pass sync: first using WB_SYNC_NONE, then WB_SYNC_ALL */ static int nfs_write_mapping(struct address_space *mapping, int how) { struct writeback_control wbc = { .bdi = mapping->backing_dev_info, .sync_mode = WB_SYNC_NONE, .nr_to_write = LONG_MAX, .range_start = 0, .range_end = LLONG_MAX, .for_writepages = 1, }; int ret; ret = __nfs_write_mapping(mapping, &wbc, how); if (ret < 0) return ret; wbc.sync_mode = WB_SYNC_ALL; return __nfs_write_mapping(mapping, &wbc, how); } /* * flush the inode to disk. */ int nfs_wb_all(struct inode *inode) { return nfs_write_mapping(inode->i_mapping, 0); } int nfs_wb_nocommit(struct inode *inode) { return nfs_write_mapping(inode->i_mapping, FLUSH_NOCOMMIT); } int nfs_wb_page_cancel(struct inode *inode, struct page *page) { struct nfs_page *req; loff_t range_start = page_offset(page); loff_t range_end = range_start + (loff_t)(PAGE_CACHE_SIZE - 1); struct writeback_control wbc = { .bdi = page->mapping->backing_dev_info, .sync_mode = WB_SYNC_ALL, .nr_to_write = LONG_MAX, .range_start = range_start, .range_end = range_end, }; int ret = 0; BUG_ON(!PageLocked(page)); for (;;) { req = nfs_page_find_request(page); if (req == NULL) goto out; if (test_bit(PG_CLEAN, &req->wb_flags)) { nfs_release_request(req); break; } if (nfs_lock_request_dontget(req)) { nfs_inode_remove_request(req); /* * In case nfs_inode_remove_request has marked the * page as being dirty */ cancel_dirty_page(page, PAGE_CACHE_SIZE); nfs_unlock_request(req); break; } ret = nfs_wait_on_request(req); if (ret < 0) goto out; } if (!PagePrivate(page)) return 0; ret = nfs_sync_mapping_wait(page->mapping, &wbc, FLUSH_INVALIDATE); out: return ret; } static int nfs_wb_page_priority(struct inode *inode, struct page *page, int how) { loff_t range_start = page_offset(page); loff_t range_end = range_start + (loff_t)(PAGE_CACHE_SIZE - 1); struct writeback_control wbc = { .bdi = page->mapping->backing_dev_info, .sync_mode = WB_SYNC_ALL, .nr_to_write = LONG_MAX, .range_start = range_start, .range_end = range_end, }; int ret; do { if (clear_page_dirty_for_io(page)) { ret = nfs_writepage_locked(page, &wbc); if (ret < 0) goto out_error; } else if (!PagePrivate(page)) break; ret = nfs_sync_mapping_wait(page->mapping, &wbc, how); if (ret < 0) goto out_error; } while (PagePrivate(page)); return 0; out_error: __mark_inode_dirty(inode, I_DIRTY_PAGES); return ret; } /* * Write back all requests on one page - we do this before reading it. */ int nfs_wb_page(struct inode *inode, struct page* page) { return nfs_wb_page_priority(inode, page, FLUSH_STABLE); } int __init nfs_init_writepagecache(void) { nfs_wdata_cachep = kmem_cache_create("nfs_write_data", sizeof(struct nfs_write_data), 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) return -ENOMEM; nfs_commit_mempool = mempool_create_slab_pool(MIN_POOL_COMMIT, nfs_wdata_cachep); if (nfs_commit_mempool == NULL) return -ENOMEM; /* * 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; } void nfs_destroy_writepagecache(void) { mempool_destroy(nfs_commit_mempool); mempool_destroy(nfs_wdata_mempool); kmem_cache_destroy(nfs_wdata_cachep); }