/* * 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/migrate.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 <linux/export.h> #include <asm/uaccess.h> #include "delegation.h" #include "internal.h" #include "iostat.h" #include "nfs4_fs.h" #include "fscache.h" #include "pnfs.h" #define NFSDBG_FACILITY NFSDBG_PAGECACHE #define MIN_POOL_WRITE (32) #define MIN_POOL_COMMIT (4) /* * Local function declarations */ static void nfs_redirty_request(struct nfs_page *req); static const struct rpc_call_ops nfs_write_common_ops; 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 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 = mempool_alloc(nfs_commit_mempool, GFP_NOFS); if (p) { 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); struct nfs_write_header *nfs_writehdr_alloc(void) { struct nfs_write_header *p = mempool_alloc(nfs_wdata_mempool, GFP_NOFS); if (p) { struct nfs_pgio_header *hdr = &p->header; memset(p, 0, sizeof(*p)); INIT_LIST_HEAD(&hdr->pages); INIT_LIST_HEAD(&hdr->rpc_list); spin_lock_init(&hdr->lock); atomic_set(&hdr->refcnt, 0); } return p; } static struct nfs_write_data *nfs_writedata_alloc(struct nfs_pgio_header *hdr, unsigned int pagecount) { struct nfs_write_data *data, *prealloc; prealloc = &container_of(hdr, struct nfs_write_header, header)->rpc_data; if (prealloc->header == NULL) data = prealloc; else data = kzalloc(sizeof(*data), GFP_KERNEL); if (!data) goto out; if (nfs_pgarray_set(&data->pages, pagecount)) { data->header = hdr; atomic_inc(&hdr->refcnt); } else { if (data != prealloc) kfree(data); data = NULL; } out: return data; } void nfs_writehdr_free(struct nfs_pgio_header *hdr) { struct nfs_write_header *whdr = container_of(hdr, struct nfs_write_header, header); mempool_free(whdr, nfs_wdata_mempool); } void nfs_writedata_release(struct nfs_write_data *wdata) { struct nfs_pgio_header *hdr = wdata->header; struct nfs_write_header *write_header = container_of(hdr, struct nfs_write_header, header); put_nfs_open_context(wdata->args.context); if (wdata->pages.pagevec != wdata->pages.page_array) kfree(wdata->pages.pagevec); if (wdata != &write_header->rpc_data) kfree(wdata); else wdata->header = NULL; if (atomic_dec_and_test(&hdr->refcnt)) hdr->completion_ops->completion(hdr); } 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 || wbc->for_background) return FLUSH_LOWPRI | FLUSH_COND_STABLE; return FLUSH_COND_STABLE; } /* * 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, BLK_RW_ASYNC); } } 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, BLK_RW_ASYNC); } static struct nfs_page *nfs_find_and_lock_request(struct page *page, bool nonblock) { 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) break; if (nfs_lock_request(req)) break; /* Note: If we hold the page lock, as is the case in nfs_writepage, * then the call to nfs_lock_request() 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); if (!nonblock) ret = nfs_wait_on_request(req); else ret = -EAGAIN; nfs_release_request(req); if (ret != 0) return ERR_PTR(ret); spin_lock(&inode->i_lock); } spin_unlock(&inode->i_lock); return 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 nfs_pageio_descriptor *pgio, struct page *page, bool nonblock) { struct nfs_page *req; int ret = 0; req = nfs_find_and_lock_request(page, nonblock); if (!req) goto out; ret = PTR_ERR(req); if (IS_ERR(req)) goto out; ret = nfs_set_page_writeback(page); BUG_ON(ret != 0); BUG_ON(test_bit(PG_CLEAN, &req->wb_flags)); if (!nfs_pageio_add_request(pgio, req)) { nfs_redirty_request(req); ret = pgio->pg_error; } out: return ret; } static int nfs_do_writepage(struct page *page, struct writeback_control *wbc, struct nfs_pageio_descriptor *pgio) { struct inode *inode = page->mapping->host; int ret; nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGE); nfs_add_stats(inode, NFSIOS_WRITEPAGES, 1); nfs_pageio_cond_complete(pgio, page->index); ret = nfs_page_async_flush(pgio, page, wbc->sync_mode == WB_SYNC_NONE); if (ret == -EAGAIN) { redirty_page_for_writepage(wbc, page); ret = 0; } return ret; } /* * 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), &nfs_async_write_completion_ops); 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; unsigned long *bitlock = &NFS_I(inode)->flags; struct nfs_pageio_descriptor pgio; int err; /* Stop dirtying of new pages while we sync */ err = wait_on_bit_lock(bitlock, NFS_INO_FLUSHING, nfs_wait_bit_killable, TASK_KILLABLE); if (err) goto out_err; nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGES); nfs_pageio_init_write(&pgio, inode, wb_priority(wbc), &nfs_async_write_completion_ops); err = write_cache_pages(mapping, wbc, nfs_writepages_callback, &pgio); nfs_pageio_complete(&pgio); clear_bit_unlock(NFS_INO_FLUSHING, bitlock); smp_mb__after_clear_bit(); wake_up_bit(bitlock, NFS_INO_FLUSHING); if (err < 0) goto out_err; err = pgio.pg_error; 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 inode *inode, struct nfs_page *req) { struct nfs_inode *nfsi = NFS_I(inode); /* Lock the request! */ nfs_lock_request(req); spin_lock(&inode->i_lock); if (!nfsi->npages && nfs_have_delegation(inode, FMODE_WRITE)) inode->i_version++; set_bit(PG_MAPPED, &req->wb_flags); SetPagePrivate(req->wb_page); set_page_private(req->wb_page, (unsigned long)req); nfsi->npages++; kref_get(&req->wb_kref); spin_unlock(&inode->i_lock); } /* * Remove a write request from an inode */ static void nfs_inode_remove_request(struct nfs_page *req) { struct inode *inode = req->wb_context->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); clear_bit(PG_MAPPED, &req->wb_flags); nfsi->npages--; spin_unlock(&inode->i_lock); 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) /** * nfs_request_add_commit_list - 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 _not_ hold the cinfo->lock, but must be * holding the nfs_page lock. */ void nfs_request_add_commit_list(struct nfs_page *req, struct list_head *dst, struct nfs_commit_info *cinfo) { set_bit(PG_CLEAN, &(req)->wb_flags); spin_lock(cinfo->lock); nfs_list_add_request(req, dst); cinfo->mds->ncommit++; spin_unlock(cinfo->lock); if (!cinfo->dreq) { 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(req->wb_context->dentry->d_inode, I_DIRTY_DATASYNC); } } 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); 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->lock = &inode->i_lock; 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) { if (pnfs_mark_request_commit(req, lseg, cinfo)) return; nfs_request_add_commit_list(req, &cinfo->mds->list, cinfo); } static void nfs_clear_page_commit(struct page *page) { dec_zone_page_state(page, NR_UNSTABLE_NFS); dec_bdi_stat(page->mapping->backing_dev_info, BDI_RECLAIMABLE); } static void nfs_clear_request_commit(struct nfs_page *req) { if (test_bit(PG_CLEAN, &req->wb_flags)) { struct inode *inode = req->wb_context->dentry->d_inode; struct nfs_commit_info cinfo; nfs_init_cinfo_from_inode(&cinfo, inode); if (!pnfs_clear_request_commit(req, &cinfo)) { spin_lock(cinfo.lock); nfs_request_remove_commit_list(req, &cinfo); spin_unlock(cinfo.lock); } nfs_clear_page_commit(req->wb_page); } } static inline int nfs_write_need_commit(struct nfs_write_data *data) { if (data->verf.committed == NFS_DATA_SYNC) return data->header->lseg == NULL; return data->verf.committed != NFS_FILE_SYNC; } #else static void nfs_init_cinfo_from_inode(struct nfs_commit_info *cinfo, struct inode *inode) { } void nfs_init_cinfo(struct nfs_commit_info *cinfo, struct inode *inode, struct nfs_direct_req *dreq) { } void nfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg, struct nfs_commit_info *cinfo) { } static void nfs_clear_request_commit(struct nfs_page *req) { } static inline int nfs_write_need_commit(struct nfs_write_data *data) { return 0; } #endif 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)) { nfs_set_pageerror(req->wb_page); nfs_context_set_write_error(req->wb_context, hdr->error); goto remove_req; } if (test_bit(NFS_IOHDR_NEED_RESCHED, &hdr->flags)) { nfs_mark_request_dirty(req); goto next; } if (test_bit(NFS_IOHDR_NEED_COMMIT, &hdr->flags)) { nfs_mark_request_commit(req, hdr->lseg, &cinfo); goto next; } remove_req: nfs_inode_remove_request(req); next: nfs_unlock_request(req); nfs_end_page_writeback(req->wb_page); nfs_release_request(req); } out: hdr->release(hdr); } #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4) static unsigned long nfs_reqs_to_commit(struct nfs_commit_info *cinfo) { return cinfo->mds->ncommit; } /* cinfo->lock 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) { if (!nfs_lock_request(req)) continue; kref_get(&req->wb_kref); if (cond_resched_lock(cinfo->lock)) list_safe_reset_next(req, tmp, wb_list); nfs_request_remove_commit_list(req, cinfo); nfs_list_add_request(req, dst); ret++; if ((ret == max) && !cinfo->dreq) break; } return ret; } /* * 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; spin_lock(cinfo->lock); if (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); } spin_unlock(cinfo->lock); return ret; } #else static unsigned long nfs_reqs_to_commit(struct nfs_commit_info *cinfo) { return 0; } int nfs_scan_commit(struct inode *inode, struct list_head *dst, struct nfs_commit_info *cinfo) { 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_lock_request(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); } /* 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); if (req) nfs_clear_request_commit(req); 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; 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; nfs_inode_add_request(inode, req); 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_mark_request_dirty(req); nfs_unlock_and_release_request(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 || req->wb_lock_context->lockowner != current->files || req->wb_lock_context->pid != current->tgid; 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 bool nfs_write_pageuptodate(struct page *page, struct inode *inode) { if (nfs_have_delegated_attributes(inode)) goto out; if (NFS_I(inode)->cache_validity & NFS_INO_REVAL_PAGECACHE) return false; out: return PageUptodate(page) != 0; } /* * 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_DSYNC)) { 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 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; } int nfs_initiate_write(struct rpc_clnt *clnt, struct nfs_write_data *data, const struct rpc_call_ops *call_ops, int how, int flags) { struct inode *inode = data->header->inode; int priority = flush_task_priority(how); struct rpc_task *task; struct rpc_message msg = { .rpc_argp = &data->args, .rpc_resp = &data->res, .rpc_cred = data->header->cred, }; struct rpc_task_setup task_setup_data = { .rpc_client = clnt, .task = &data->task, .rpc_message = &msg, .callback_ops = call_ops, .callback_data = data, .workqueue = nfsiod_workqueue, .flags = RPC_TASK_ASYNC | flags, .priority = priority, }; int ret = 0; /* 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), data->args.count, (unsigned long long)data->args.offset); task = rpc_run_task(&task_setup_data); if (IS_ERR(task)) { ret = PTR_ERR(task); goto out; } if (how & FLUSH_SYNC) { ret = rpc_wait_for_completion_task(task); if (ret == 0) ret = task->tk_status; } rpc_put_task(task); out: return ret; } EXPORT_SYMBOL_GPL(nfs_initiate_write); /* * Set up the argument/result storage required for the RPC call. */ static void nfs_write_rpcsetup(struct nfs_write_data *data, unsigned int count, unsigned int offset, int how, struct nfs_commit_info *cinfo) { struct nfs_page *req = data->header->req; /* Set up the RPC argument and reply structs * NB: take care not to mess about with data->commit et al. */ data->args.fh = NFS_FH(data->header->inode); data->args.offset = req_offset(req) + offset; /* pnfs_set_layoutcommit needs this */ data->mds_offset = data->args.offset; data->args.pgbase = req->wb_pgbase + offset; data->args.pages = data->pages.pagevec; data->args.count = count; data->args.context = get_nfs_open_context(req->wb_context); data->args.lock_context = req->wb_lock_context; data->args.stable = NFS_UNSTABLE; switch (how & (FLUSH_STABLE | FLUSH_COND_STABLE)) { case 0: break; case FLUSH_COND_STABLE: if (nfs_reqs_to_commit(cinfo)) break; default: 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); } static int nfs_do_write(struct nfs_write_data *data, const struct rpc_call_ops *call_ops, int how) { struct inode *inode = data->header->inode; return nfs_initiate_write(NFS_CLIENT(inode), data, call_ops, how, 0); } static int nfs_do_multiple_writes(struct list_head *head, const struct rpc_call_ops *call_ops, int how) { struct nfs_write_data *data; int ret = 0; while (!list_empty(head)) { int ret2; data = list_first_entry(head, struct nfs_write_data, list); list_del_init(&data->list); ret2 = nfs_do_write(data, call_ops, how); if (ret == 0) ret = ret2; } return ret; } /* 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_unlock_request(req); nfs_end_page_writeback(req->wb_page); nfs_release_request(req); } static void nfs_async_write_error(struct list_head *head) { struct nfs_page *req; while (!list_empty(head)) { req = nfs_list_entry(head->next); nfs_list_remove_request(req); nfs_redirty_request(req); } } static const struct nfs_pgio_completion_ops nfs_async_write_completion_ops = { .error_cleanup = nfs_async_write_error, .completion = nfs_write_completion, }; static void nfs_flush_error(struct nfs_pageio_descriptor *desc, struct nfs_pgio_header *hdr) { set_bit(NFS_IOHDR_REDO, &hdr->flags); while (!list_empty(&hdr->rpc_list)) { struct nfs_write_data *data = list_first_entry(&hdr->rpc_list, struct nfs_write_data, list); list_del(&data->list); nfs_writedata_release(data); } desc->pg_completion_ops->error_cleanup(&desc->pg_list); } /* * Generate multiple small requests to write out a single * contiguous dirty area on one page. */ static int nfs_flush_multi(struct nfs_pageio_descriptor *desc, struct nfs_pgio_header *hdr) { struct nfs_page *req = hdr->req; struct page *page = req->wb_page; struct nfs_write_data *data; size_t wsize = desc->pg_bsize, nbytes; unsigned int offset; int requests = 0; struct nfs_commit_info cinfo; nfs_init_cinfo(&cinfo, desc->pg_inode, desc->pg_dreq); if ((desc->pg_ioflags & FLUSH_COND_STABLE) && (desc->pg_moreio || nfs_reqs_to_commit(&cinfo) || desc->pg_count > wsize)) desc->pg_ioflags &= ~FLUSH_COND_STABLE; offset = 0; nbytes = desc->pg_count; do { size_t len = min(nbytes, wsize); data = nfs_writedata_alloc(hdr, 1); if (!data) { nfs_flush_error(desc, hdr); return -ENOMEM; } data->pages.pagevec[0] = page; nfs_write_rpcsetup(data, len, offset, desc->pg_ioflags, &cinfo); list_add(&data->list, &hdr->rpc_list); requests++; nbytes -= len; offset += len; } while (nbytes != 0); nfs_list_remove_request(req); nfs_list_add_request(req, &hdr->pages); desc->pg_rpc_callops = &nfs_write_common_ops; return 0; } /* * 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 nfs_pageio_descriptor *desc, struct nfs_pgio_header *hdr) { struct nfs_page *req; struct page **pages; struct nfs_write_data *data; struct list_head *head = &desc->pg_list; struct nfs_commit_info cinfo; data = nfs_writedata_alloc(hdr, nfs_page_array_len(desc->pg_base, desc->pg_count)); if (!data) { nfs_flush_error(desc, hdr); return -ENOMEM; } nfs_init_cinfo(&cinfo, desc->pg_inode, desc->pg_dreq); pages = data->pages.pagevec; while (!list_empty(head)) { req = nfs_list_entry(head->next); nfs_list_remove_request(req); nfs_list_add_request(req, &hdr->pages); *pages++ = req->wb_page; } if ((desc->pg_ioflags & FLUSH_COND_STABLE) && (desc->pg_moreio || nfs_reqs_to_commit(&cinfo))) desc->pg_ioflags &= ~FLUSH_COND_STABLE; /* Set up the argument struct */ nfs_write_rpcsetup(data, desc->pg_count, 0, desc->pg_ioflags, &cinfo); list_add(&data->list, &hdr->rpc_list); desc->pg_rpc_callops = &nfs_write_common_ops; return 0; } int nfs_generic_flush(struct nfs_pageio_descriptor *desc, struct nfs_pgio_header *hdr) { if (desc->pg_bsize < PAGE_CACHE_SIZE) return nfs_flush_multi(desc, hdr); return nfs_flush_one(desc, hdr); } static int nfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc) { struct nfs_write_header *whdr; struct nfs_pgio_header *hdr; int ret; whdr = nfs_writehdr_alloc(); if (!whdr) { desc->pg_completion_ops->error_cleanup(&desc->pg_list); return -ENOMEM; } hdr = &whdr->header; nfs_pgheader_init(desc, hdr, nfs_writehdr_free); atomic_inc(&hdr->refcnt); ret = nfs_generic_flush(desc, hdr); if (ret == 0) ret = nfs_do_multiple_writes(&hdr->rpc_list, desc->pg_rpc_callops, desc->pg_ioflags); if (atomic_dec_and_test(&hdr->refcnt)) hdr->completion_ops->completion(hdr); return ret; } static const struct nfs_pageio_ops nfs_pageio_write_ops = { .pg_test = nfs_generic_pg_test, .pg_doio = nfs_generic_pg_writepages, }; void nfs_pageio_init_write_mds(struct nfs_pageio_descriptor *pgio, struct inode *inode, int ioflags, const struct nfs_pgio_completion_ops *compl_ops) { nfs_pageio_init(pgio, inode, &nfs_pageio_write_ops, compl_ops, NFS_SERVER(inode)->wsize, ioflags); } void nfs_pageio_reset_write_mds(struct nfs_pageio_descriptor *pgio) { pgio->pg_ops = &nfs_pageio_write_ops; pgio->pg_bsize = NFS_SERVER(pgio->pg_inode)->wsize; } EXPORT_SYMBOL_GPL(nfs_pageio_reset_write_mds); void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio, struct inode *inode, int ioflags, const struct nfs_pgio_completion_ops *compl_ops) { if (!pnfs_pageio_init_write(pgio, inode, ioflags, compl_ops)) nfs_pageio_init_write_mds(pgio, inode, ioflags, compl_ops); } void nfs_write_prepare(struct rpc_task *task, void *calldata) { struct nfs_write_data *data = calldata; NFS_PROTO(data->header->inode)->write_rpc_prepare(task, data); } 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); } /* * 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_common(struct rpc_task *task, void *calldata) { struct nfs_write_data *data = calldata; nfs_writeback_done(task, data); } static void nfs_writeback_release_common(void *calldata) { struct nfs_write_data *data = calldata; struct nfs_pgio_header *hdr = data->header; int status = data->task.tk_status; struct nfs_page *req = hdr->req; if ((status >= 0) && nfs_write_need_commit(data)) { spin_lock(&hdr->lock); if (test_bit(NFS_IOHDR_NEED_RESCHED, &hdr->flags)) ; /* Do nothing */ else if (!test_and_set_bit(NFS_IOHDR_NEED_COMMIT, &hdr->flags)) memcpy(&req->wb_verf, &data->verf, sizeof(req->wb_verf)); else if (memcmp(&req->wb_verf, &data->verf, sizeof(req->wb_verf))) set_bit(NFS_IOHDR_NEED_RESCHED, &hdr->flags); spin_unlock(&hdr->lock); } nfs_writedata_release(data); } static const struct rpc_call_ops nfs_write_common_ops = { .rpc_call_prepare = nfs_write_prepare, .rpc_call_done = nfs_writeback_done_common, .rpc_release = nfs_writeback_release_common, }; /* * This function is called when the WRITE call is complete. */ void nfs_writeback_done(struct rpc_task *task, struct nfs_write_data *data) { struct nfs_writeargs *argp = &data->args; struct nfs_writeres *resp = &data->res; struct inode *inode = data->header->inode; 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(inode)->write_done(task, data); if (status != 0) return; nfs_add_stats(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; /* 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, resp->verf->committed, argp->stable); complain = jiffies + 300 * HZ; } } #endif if (task->tk_status < 0) nfs_set_pgio_error(data->header, task->tk_status, argp->offset); else if (resp->count < argp->count) { static unsigned long complain; /* This a short write! */ nfs_inc_stats(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(data->header, -EIO, argp->offset); task->tk_status = -EIO; return; } /* Was this an NFSv2 write or an NFSv3 stable write? */ if (resp->verf->committed != NFS_UNSTABLE) { /* Resend from where the server left off */ data->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; } rpc_restart_call_prepare(task); } } #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4) static int nfs_commit_set_lock(struct nfs_inode *nfsi, int may_wait) { int ret; if (!test_and_set_bit(NFS_INO_COMMIT, &nfsi->flags)) return 1; if (!may_wait) return 0; ret = out_of_line_wait_on_bit_lock(&nfsi->flags, NFS_INO_COMMIT, nfs_wait_bit_killable, TASK_KILLABLE); return (ret < 0) ? ret : 1; } static void nfs_commit_clear_lock(struct nfs_inode *nfsi) { clear_bit(NFS_INO_COMMIT, &nfsi->flags); smp_mb__after_clear_bit(); wake_up_bit(&nfsi->flags, NFS_INO_COMMIT); } 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 rpc_call_ops *call_ops, int how, int flags) { 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, }; /* Set up the initial task struct. */ NFS_PROTO(data->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); if (how & FLUSH_SYNC) rpc_wait_for_completion_task(task); rpc_put_task(task); return 0; } EXPORT_SYMBOL_GPL(nfs_initiate_commit); /* * 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 = nfs_list_entry(head->next); struct inode *inode = first->wb_context->dentry->d_inode; /* 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 = first->wb_context->cred; data->lseg = lseg; /* reference transferred */ 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(first->wb_context); data->res.fattr = &data->fattr; data->res.verf = &data->verf; nfs_fattr_init(&data->fattr); } 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) { 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); if (!cinfo->dreq) { dec_zone_page_state(req->wb_page, NR_UNSTABLE_NFS); dec_bdi_stat(req->wb_page->mapping->backing_dev_info, BDI_RECLAIMABLE); } nfs_unlock_and_release_request(req); } } EXPORT_SYMBOL_GPL(nfs_retry_commit); /* * 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; data = nfs_commitdata_alloc(); if (!data) goto out_bad; /* Set up the argument struct */ nfs_init_commit(data, head, NULL, cinfo); atomic_inc(&cinfo->mds->rpcs_out); return nfs_initiate_commit(NFS_CLIENT(inode), data, data->mds_ops, how, 0); out_bad: nfs_retry_commit(head, NULL, cinfo); cinfo->completion_ops->error_cleanup(NFS_I(inode)); return -ENOMEM; } /* * COMMIT call returned */ static void nfs_commit_done(struct rpc_task *task, void *calldata) { struct nfs_commit_data *data = calldata; dprintk("NFS: %5u nfs_commit_done (status %d)\n", task->tk_pid, task->tk_status); /* Call the NFS version-specific code */ NFS_PROTO(data->inode)->commit_done(task, data); } static void nfs_commit_release_pages(struct nfs_commit_data *data) { struct nfs_page *req; int status = data->task.tk_status; struct nfs_commit_info cinfo; while (!list_empty(&data->pages)) { req = nfs_list_entry(data->pages.next); nfs_list_remove_request(req); nfs_clear_page_commit(req->wb_page); dprintk("NFS: commit (%s/%lld %d@%lld)", req->wb_context->dentry->d_sb->s_id, (long long)NFS_FILEID(req->wb_context->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_unlock_and_release_request(req); } nfs_init_cinfo(&cinfo, data->inode, data->dreq); if (atomic_dec_and_test(&cinfo.mds->rpcs_out)) nfs_commit_clear_lock(NFS_I(data->inode)); } 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, .error_cleanup = nfs_commit_clear_lock, }; 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; } int nfs_commit_inode(struct inode *inode, int how) { LIST_HEAD(head); struct nfs_commit_info cinfo; int may_wait = how & FLUSH_SYNC; int res; res = nfs_commit_set_lock(NFS_I(inode), may_wait); if (res <= 0) goto out_mark_dirty; nfs_init_cinfo_from_inode(&cinfo, inode); res = nfs_scan_commit(inode, &head, &cinfo); if (res) { int error; error = nfs_generic_commit_list(inode, &head, how, &cinfo); if (error < 0) return error; if (!may_wait) goto out_mark_dirty; error = wait_on_bit(&NFS_I(inode)->flags, NFS_INO_COMMIT, nfs_wait_bit_killable, TASK_KILLABLE); if (error < 0) return error; } else nfs_commit_clear_lock(NFS_I(inode)); return res; /* Note: If we exit without ensuring that the commit is complete, * we must mark the inode as dirty. Otherwise, future calls to * sync_inode() with the WB_SYNC_ALL flag set will fail to ensure * that the data is on the disk. */ out_mark_dirty: __mark_inode_dirty(inode, I_DIRTY_DATASYNC); return res; } static int nfs_commit_unstable_pages(struct inode *inode, struct writeback_control *wbc) { struct nfs_inode *nfsi = NFS_I(inode); int flags = FLUSH_SYNC; int ret = 0; /* no commits means nothing needs to be done */ if (!nfsi->commit_info.ncommit) return ret; if (wbc->sync_mode == WB_SYNC_NONE) { /* Don't commit yet if this is a non-blocking flush and there * are a lot of outstanding writes for this mapping. */ if (nfsi->commit_info.ncommit <= (nfsi->npages >> 1)) goto out_mark_dirty; /* don't wait for the COMMIT response */ flags = 0; } ret = nfs_commit_inode(inode, flags); if (ret >= 0) { if (wbc->sync_mode == WB_SYNC_NONE) { if (ret < wbc->nr_to_write) wbc->nr_to_write -= ret; else wbc->nr_to_write = 0; } return 0; } out_mark_dirty: __mark_inode_dirty(inode, I_DIRTY_DATASYNC); return ret; } #else static int nfs_commit_unstable_pages(struct inode *inode, struct writeback_control *wbc) { return 0; } #endif int nfs_write_inode(struct inode *inode, struct writeback_control *wbc) { int ret; ret = nfs_commit_unstable_pages(inode, wbc); if (ret >= 0 && test_bit(NFS_INO_LAYOUTCOMMIT, &NFS_I(inode)->flags)) { int status; bool sync = true; if (wbc->sync_mode == WB_SYNC_NONE) sync = false; status = pnfs_layoutcommit_inode(inode, sync); if (status < 0) return status; } return ret; } /* * flush the inode to disk. */ int nfs_wb_all(struct inode *inode) { struct writeback_control wbc = { .sync_mode = WB_SYNC_ALL, .nr_to_write = LONG_MAX, .range_start = 0, .range_end = LLONG_MAX, }; return sync_inode(inode, &wbc); } int nfs_wb_page_cancel(struct inode *inode, struct page *page) { struct nfs_page *req; int ret = 0; BUG_ON(!PageLocked(page)); for (;;) { wait_on_page_writeback(page); req = nfs_page_find_request(page); if (req == NULL) break; if (nfs_lock_request(req)) { nfs_clear_request_commit(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_and_release_request(req); break; } ret = nfs_wait_on_request(req); nfs_release_request(req); if (ret < 0) break; } 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) { loff_t range_start = page_offset(page); loff_t range_end = range_start + (loff_t)(PAGE_CACHE_SIZE - 1); struct writeback_control wbc = { .sync_mode = WB_SYNC_ALL, .nr_to_write = 0, .range_start = range_start, .range_end = range_end, }; int ret; for (;;) { wait_on_page_writeback(page); if (clear_page_dirty_for_io(page)) { ret = nfs_writepage_locked(page, &wbc); if (ret < 0) goto out_error; continue; } if (!PagePrivate(page)) break; ret = nfs_commit_inode(inode, FLUSH_SYNC); if (ret < 0) goto out_error; } return 0; out_error: return ret; } #ifdef CONFIG_MIGRATION int nfs_migrate_page(struct address_space *mapping, struct page *newpage, struct page *page, enum migrate_mode mode) { /* * If PagePrivate is set, then the page 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 page lock. */ if (PagePrivate(page)) return -EBUSY; nfs_fscache_release_page(page, GFP_KERNEL); return migrate_page(mapping, newpage, page, mode); } #endif int __init nfs_init_writepagecache(void) { nfs_wdata_cachep = kmem_cache_create("nfs_write_data", sizeof(struct nfs_write_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) return -ENOMEM; nfs_cdata_cachep = kmem_cache_create("nfs_commit_data", sizeof(struct nfs_commit_data), 0, SLAB_HWCACHE_ALIGN, NULL); if (nfs_cdata_cachep == 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); }