zte's code,first commit
Change-Id: I9a04da59e459a9bc0d67f101f700d9d7dc8d681b
diff --git a/ap/os/linux/linux-3.4.x/fs/nfs/write.c b/ap/os/linux/linux-3.4.x/fs/nfs/write.c
new file mode 100644
index 0000000..da8fd94
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/fs/nfs/write.c
@@ -0,0 +1,1796 @@
+/*
+ * 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_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;
+}
+EXPORT_SYMBOL_GPL(nfs_commitdata_alloc);
+
+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);
+}
+EXPORT_SYMBOL_GPL(nfs_commit_free);
+
+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;
+}
+
+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(struct nfs_write_data *wdata)
+{
+ 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 || 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);
+
+ page_cache_get(page);
+ 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);
+ page_cache_release(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_dontget(req))
+ break;
+ /* Note: If we hold the page lock, as is the case in nfs_writepage,
+ * then the call to nfs_lock_request_dontget() 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));
+ 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));
+ 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_dontget(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
+ * @head: commit list head
+ *
+ * This sets the PG_CLEAN bit, updates the inode global count of
+ * number of outstanding requests requiring a commit as well as
+ * the MM page stats.
+ *
+ * The caller must _not_ hold the inode->i_lock, but must be
+ * holding the nfs_page lock.
+ */
+void
+nfs_request_add_commit_list(struct nfs_page *req, struct list_head *head)
+{
+ struct inode *inode = req->wb_context->dentry->d_inode;
+
+ set_bit(PG_CLEAN, &(req)->wb_flags);
+ spin_lock(&inode->i_lock);
+ nfs_list_add_request(req, head);
+ NFS_I(inode)->ncommit++;
+ 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);
+}
+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
+ *
+ * This clears the PG_CLEAN bit, and updates the inode global count of
+ * number of outstanding requests requiring a commit
+ * It does not update the MM page stats.
+ *
+ * The caller _must_ hold the inode->i_lock and the nfs_page lock.
+ */
+void
+nfs_request_remove_commit_list(struct nfs_page *req)
+{
+ struct inode *inode = req->wb_context->dentry->d_inode;
+
+ if (!test_and_clear_bit(PG_CLEAN, &(req)->wb_flags))
+ return;
+ nfs_list_remove_request(req);
+ NFS_I(inode)->ncommit--;
+}
+EXPORT_SYMBOL_GPL(nfs_request_remove_commit_list);
+
+
+/*
+ * Add a request to the inode's commit list.
+ */
+static void
+nfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg)
+{
+ struct inode *inode = req->wb_context->dentry->d_inode;
+
+ if (pnfs_mark_request_commit(req, lseg))
+ return;
+ nfs_request_add_commit_list(req, &NFS_I(inode)->commit_list);
+}
+
+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;
+
+ if (!pnfs_clear_request_commit(req)) {
+ spin_lock(&inode->i_lock);
+ nfs_request_remove_commit_list(req);
+ spin_unlock(&inode->i_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->lseg == NULL;
+ else
+ return data->verf.committed != NFS_FILE_SYNC;
+}
+
+static inline
+int nfs_reschedule_unstable_write(struct nfs_page *req,
+ struct nfs_write_data *data)
+{
+ if (test_and_clear_bit(PG_NEED_COMMIT, &req->wb_flags)) {
+ nfs_mark_request_commit(req, data->lseg);
+ return 1;
+ }
+ if (test_and_clear_bit(PG_NEED_RESCHED, &req->wb_flags)) {
+ nfs_mark_request_dirty(req);
+ return 1;
+ }
+ return 0;
+}
+#else
+static void
+nfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg)
+{
+}
+
+static void
+nfs_clear_request_commit(struct nfs_page *req)
+{
+}
+
+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,
+ struct nfs_write_data *data)
+{
+ return 0;
+}
+#endif
+
+#if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
+static int
+nfs_need_commit(struct nfs_inode *nfsi)
+{
+ return nfsi->ncommit > 0;
+}
+
+/* i_lock held by caller */
+static int
+nfs_scan_commit_list(struct list_head *src, struct list_head *dst, int max,
+ spinlock_t *lock)
+{
+ struct nfs_page *req, *tmp;
+ int ret = 0;
+
+ list_for_each_entry_safe(req, tmp, src, wb_list) {
+ if (!nfs_lock_request(req))
+ continue;
+ if (cond_resched_lock(lock))
+ list_safe_reset_next(req, tmp, wb_list);
+ nfs_request_remove_commit_list(req);
+ nfs_list_add_request(req, dst);
+ ret++;
+ if (ret == max)
+ break;
+ }
+ return ret;
+}
+
+/*
+ * nfs_scan_commit - Scan an inode for commit requests
+ * @inode: NFS inode to scan
+ * @dst: destination list
+ *
+ * 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)
+{
+ struct nfs_inode *nfsi = NFS_I(inode);
+ int ret = 0;
+
+ spin_lock(&inode->i_lock);
+ if (nfsi->ncommit > 0) {
+ const int max = INT_MAX;
+
+ ret = nfs_scan_commit_list(&nfsi->commit_list, dst, max,
+ &inode->i_lock);
+ ret += pnfs_scan_commit_lists(inode, max - ret,
+ &inode->i_lock);
+ }
+ spin_unlock(&inode->i_lock);
+ return ret;
+}
+
+#else
+static inline int nfs_need_commit(struct nfs_inode *nfsi)
+{
+ return 0;
+}
+
+static inline int nfs_scan_commit(struct inode *inode, struct list_head *dst)
+{
+ 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_dontget(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_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 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_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 void nfs_writepage_release(struct nfs_page *req,
+ struct nfs_write_data *data)
+{
+ struct page *page = req->wb_page;
+
+ if (PageError(req->wb_page) || !nfs_reschedule_unstable_write(req, data))
+ nfs_inode_remove_request(req);
+ nfs_unlock_request(req);
+ nfs_end_page_writeback(page);
+}
+
+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 nfs_write_data *data,
+ struct rpc_clnt *clnt,
+ const struct rpc_call_ops *call_ops,
+ int how)
+{
+ struct inode *inode = data->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->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,
+ .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_page *req,
+ struct nfs_write_data *data,
+ unsigned int count, unsigned int offset,
+ int how)
+{
+ struct inode *inode = req->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. */
+
+ data->req = req;
+ data->inode = inode = req->wb_context->dentry->d_inode;
+ data->cred = req->wb_context->cred;
+
+ data->args.fh = NFS_FH(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->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_need_commit(NFS_I(inode)))
+ 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->args.context->dentry->d_inode;
+
+ return nfs_initiate_write(data, NFS_CLIENT(inode), call_ops, how);
+}
+
+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_entry(head->next, 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)
+{
+ struct page *page = req->wb_page;
+
+ nfs_mark_request_dirty(req);
+ nfs_unlock_request(req);
+ nfs_end_page_writeback(page);
+}
+
+/*
+ * 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 list_head *res)
+{
+ struct nfs_page *req = nfs_list_entry(desc->pg_list.next);
+ struct page *page = req->wb_page;
+ struct nfs_write_data *data;
+ size_t wsize = desc->pg_bsize, nbytes;
+ unsigned int offset;
+ int requests = 0;
+ int ret = 0;
+
+ nfs_list_remove_request(req);
+
+ if ((desc->pg_ioflags & FLUSH_COND_STABLE) &&
+ (desc->pg_moreio || NFS_I(desc->pg_inode)->ncommit ||
+ 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(1);
+ if (!data)
+ goto out_bad;
+ data->pagevec[0] = page;
+ nfs_write_rpcsetup(req, data, len, offset, desc->pg_ioflags);
+ list_add(&data->list, res);
+ requests++;
+ nbytes -= len;
+ offset += len;
+ } while (nbytes != 0);
+ atomic_set(&req->wb_complete, requests);
+ desc->pg_rpc_callops = &nfs_write_partial_ops;
+ return ret;
+
+out_bad:
+ while (!list_empty(res)) {
+ data = list_entry(res->next, struct nfs_write_data, list);
+ list_del(&data->list);
+ 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 nfs_pageio_descriptor *desc, struct list_head *res)
+{
+ struct nfs_page *req;
+ struct page **pages;
+ struct nfs_write_data *data;
+ struct list_head *head = &desc->pg_list;
+ int ret = 0;
+
+ data = nfs_writedata_alloc(nfs_page_array_len(desc->pg_base,
+ desc->pg_count));
+ if (!data) {
+ while (!list_empty(head)) {
+ req = nfs_list_entry(head->next);
+ nfs_list_remove_request(req);
+ nfs_redirty_request(req);
+ }
+ ret = -ENOMEM;
+ goto out;
+ }
+ 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);
+ *pages++ = req->wb_page;
+ }
+ req = nfs_list_entry(data->pages.next);
+
+ if ((desc->pg_ioflags & FLUSH_COND_STABLE) &&
+ (desc->pg_moreio || NFS_I(desc->pg_inode)->ncommit))
+ desc->pg_ioflags &= ~FLUSH_COND_STABLE;
+
+ /* Set up the argument struct */
+ nfs_write_rpcsetup(req, data, desc->pg_count, 0, desc->pg_ioflags);
+ list_add(&data->list, res);
+ desc->pg_rpc_callops = &nfs_write_full_ops;
+out:
+ return ret;
+}
+
+int nfs_generic_flush(struct nfs_pageio_descriptor *desc, struct list_head *head)
+{
+ if (desc->pg_bsize < PAGE_CACHE_SIZE)
+ return nfs_flush_multi(desc, head);
+ return nfs_flush_one(desc, head);
+}
+
+static int nfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc)
+{
+ LIST_HEAD(head);
+ int ret;
+
+ ret = nfs_generic_flush(desc, &head);
+ if (ret == 0)
+ ret = nfs_do_multiple_writes(&head, desc->pg_rpc_callops,
+ desc->pg_ioflags);
+ 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)
+{
+ nfs_pageio_init(pgio, inode, &nfs_pageio_write_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);
+
+static void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio,
+ struct inode *inode, int ioflags)
+{
+ if (!pnfs_pageio_init_write(pgio, inode, ioflags))
+ nfs_pageio_init_write_mds(pgio, inode, 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->dentry->d_inode->i_sb->s_id,
+ (long long)
+ NFS_FILEID(data->req->wb_context->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, data);
+ nfs_writedata_release(calldata);
+}
+
+void nfs_write_prepare(struct rpc_task *task, void *calldata)
+{
+ struct nfs_write_data *data = calldata;
+ NFS_PROTO(data->inode)->write_rpc_prepare(task, data);
+}
+
+static const struct rpc_call_ops nfs_write_partial_ops = {
+ .rpc_call_prepare = nfs_write_prepare,
+ .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->dentry->d_inode->i_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_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, data->lseg);
+ dprintk(" marked for commit\n");
+ goto next;
+ }
+ dprintk(" OK\n");
+remove_request:
+ nfs_inode_remove_request(req);
+ next:
+ nfs_unlock_request(req);
+ nfs_end_page_writeback(page);
+ }
+ nfs_writedata_release(calldata);
+}
+
+static const struct rpc_call_ops nfs_write_full_ops = {
+ .rpc_call_prepare = nfs_write_prepare,
+ .rpc_call_done = nfs_writeback_done_full,
+ .rpc_release = nfs_writeback_release_full,
+};
+
+
+/*
+ * 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;
+ 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;
+ 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;
+
+ /* 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(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 */
+ 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);
+ return;
+ }
+ 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;
+}
+
+
+#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;
+}
+
+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);
+}
+EXPORT_SYMBOL_GPL(nfs_commit_clear_lock);
+
+void nfs_commitdata_release(void *data)
+{
+ struct nfs_write_data *wdata = data;
+
+ put_nfs_open_context(wdata->args.context);
+ nfs_commit_free(wdata);
+}
+EXPORT_SYMBOL_GPL(nfs_commitdata_release);
+
+int nfs_initiate_commit(struct nfs_write_data *data, struct rpc_clnt *clnt,
+ const struct rpc_call_ops *call_ops,
+ int how)
+{
+ 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,
+ .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_write_data *data,
+ struct list_head *head,
+ struct pnfs_layout_segment *lseg)
+{
+ 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->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);
+}
+EXPORT_SYMBOL_GPL(nfs_init_commit);
+
+void nfs_retry_commit(struct list_head *page_list,
+ struct pnfs_layout_segment *lseg)
+{
+ 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);
+ dec_zone_page_state(req->wb_page, NR_UNSTABLE_NFS);
+ dec_bdi_stat(req->wb_page->mapping->backing_dev_info,
+ BDI_RECLAIMABLE);
+ nfs_unlock_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_write_data *data;
+
+ data = nfs_commitdata_alloc();
+
+ if (!data)
+ goto out_bad;
+
+ /* Set up the argument struct */
+ nfs_init_commit(data, head, NULL);
+ return nfs_initiate_commit(data, NFS_CLIENT(inode), data->mds_ops, how);
+ out_bad:
+ nfs_retry_commit(head, NULL);
+ nfs_commit_clear_lock(NFS_I(inode));
+ 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 */
+ NFS_PROTO(data->inode)->commit_done(task, data);
+}
+
+void nfs_commit_release_pages(struct nfs_write_data *data)
+{
+ 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_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_request(req);
+ }
+}
+EXPORT_SYMBOL_GPL(nfs_commit_release_pages);
+
+static void nfs_commit_release(void *calldata)
+{
+ struct nfs_write_data *data = calldata;
+
+ nfs_commit_release_pages(data);
+ nfs_commit_clear_lock(NFS_I(data->inode));
+ nfs_commitdata_release(calldata);
+}
+
+static const struct rpc_call_ops nfs_commit_ops = {
+ .rpc_call_prepare = nfs_write_prepare,
+ .rpc_call_done = nfs_commit_done,
+ .rpc_release = nfs_commit_release,
+};
+
+int nfs_commit_inode(struct inode *inode, int how)
+{
+ LIST_HEAD(head);
+ 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;
+ res = nfs_scan_commit(inode, &head);
+ if (res) {
+ int error;
+
+ error = pnfs_commit_list(inode, &head, how);
+ if (error == PNFS_NOT_ATTEMPTED)
+ error = nfs_commit_list(inode, &head, how);
+ 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->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->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_dontget(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_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_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)
+ goto out_destroy_write_cache;
+
+ nfs_commit_mempool = mempool_create_slab_pool(MIN_POOL_COMMIT,
+ nfs_wdata_cachep);
+ if (nfs_commit_mempool == NULL)
+ goto out_destroy_write_mempool;
+
+ /*
+ * 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_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);
+ mempool_destroy(nfs_wdata_mempool);
+ kmem_cache_destroy(nfs_wdata_cachep);
+}
+