[T106][ZXW-22]7520V3SCV2.01.01.02P42U09_VEC_V0.8_AP_VEC origin source commit
Change-Id: Ic6e05d89ecd62fc34f82b23dcf306c93764aec4b
diff --git a/ap/os/linux/linux-3.4.x/fs/nfs/read.c b/ap/os/linux/linux-3.4.x/fs/nfs/read.c
new file mode 100644
index 0000000..0a4be28
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/fs/nfs/read.c
@@ -0,0 +1,699 @@
+/*
+ * linux/fs/nfs/read.c
+ *
+ * Block I/O for NFS
+ *
+ * Partial copy of Linus' read cache modifications to fs/nfs/file.c
+ * modified for async RPC by okir@monad.swb.de
+ */
+
+#include <linux/time.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/fcntl.h>
+#include <linux/stat.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/pagemap.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/nfs_fs.h>
+#include <linux/nfs_page.h>
+#include <linux/module.h>
+
+#include "pnfs.h"
+
+#include "nfs4_fs.h"
+#include "internal.h"
+#include "iostat.h"
+#include "fscache.h"
+
+#define NFSDBG_FACILITY NFSDBG_PAGECACHE
+
+static const struct nfs_pageio_ops nfs_pageio_read_ops;
+static const struct rpc_call_ops nfs_read_partial_ops;
+static const struct rpc_call_ops nfs_read_full_ops;
+
+static struct kmem_cache *nfs_rdata_cachep;
+
+struct nfs_read_data *nfs_readdata_alloc(unsigned int pagecount)
+{
+ struct nfs_read_data *p;
+
+ p = kmem_cache_zalloc(nfs_rdata_cachep, GFP_KERNEL);
+ if (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_KERNEL);
+ if (!p->pagevec) {
+ kmem_cache_free(nfs_rdata_cachep, p);
+ p = NULL;
+ }
+ }
+ }
+ return p;
+}
+
+void nfs_readdata_free(struct nfs_read_data *p)
+{
+ if (p && (p->pagevec != &p->page_array[0]))
+ kfree(p->pagevec);
+ kmem_cache_free(nfs_rdata_cachep, p);
+}
+
+void nfs_readdata_release(struct nfs_read_data *rdata)
+{
+ put_nfs_open_context(rdata->args.context);
+ nfs_readdata_free(rdata);
+}
+
+static
+int nfs_return_empty_page(struct page *page)
+{
+ zero_user(page, 0, PAGE_CACHE_SIZE);
+ SetPageUptodate(page);
+ unlock_page(page);
+ return 0;
+}
+
+static void nfs_readpage_truncate_uninitialised_page(struct nfs_read_data *data)
+{
+ unsigned int remainder = data->args.count - data->res.count;
+ unsigned int base = data->args.pgbase + data->res.count;
+ unsigned int pglen;
+ struct page **pages;
+
+ if (data->res.eof == 0 || remainder == 0)
+ return;
+ /*
+ * Note: "remainder" can never be negative, since we check for
+ * this in the XDR code.
+ */
+ pages = &data->args.pages[base >> PAGE_CACHE_SHIFT];
+ base &= ~PAGE_CACHE_MASK;
+ pglen = PAGE_CACHE_SIZE - base;
+ for (;;) {
+ if (remainder <= pglen) {
+ zero_user(*pages, base, remainder);
+ break;
+ }
+ zero_user(*pages, base, pglen);
+ pages++;
+ remainder -= pglen;
+ pglen = PAGE_CACHE_SIZE;
+ base = 0;
+ }
+}
+
+void nfs_pageio_init_read_mds(struct nfs_pageio_descriptor *pgio,
+ struct inode *inode)
+{
+ nfs_pageio_init(pgio, inode, &nfs_pageio_read_ops,
+ NFS_SERVER(inode)->rsize, 0);
+}
+
+void nfs_pageio_reset_read_mds(struct nfs_pageio_descriptor *pgio)
+{
+ pgio->pg_ops = &nfs_pageio_read_ops;
+ pgio->pg_bsize = NFS_SERVER(pgio->pg_inode)->rsize;
+}
+EXPORT_SYMBOL_GPL(nfs_pageio_reset_read_mds);
+
+static void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
+ struct inode *inode)
+{
+ if (!pnfs_pageio_init_read(pgio, inode))
+ nfs_pageio_init_read_mds(pgio, inode);
+}
+
+int nfs_readpage_async(struct nfs_open_context *ctx, struct inode *inode,
+ struct page *page)
+{
+ struct nfs_page *new;
+ unsigned int len;
+ struct nfs_pageio_descriptor pgio;
+
+ len = nfs_page_length(page);
+ if (len == 0)
+ return nfs_return_empty_page(page);
+ new = nfs_create_request(ctx, inode, page, 0, len);
+ if (IS_ERR(new)) {
+ unlock_page(page);
+ return PTR_ERR(new);
+ }
+ if (len < PAGE_CACHE_SIZE)
+ zero_user_segment(page, len, PAGE_CACHE_SIZE);
+
+ nfs_pageio_init_read(&pgio, inode);
+ nfs_pageio_add_request(&pgio, new);
+ nfs_pageio_complete(&pgio);
+ return 0;
+}
+
+static void nfs_readpage_release(struct nfs_page *req)
+{
+ struct inode *d_inode = req->wb_context->dentry->d_inode;
+
+ if (PageUptodate(req->wb_page))
+ nfs_readpage_to_fscache(d_inode, req->wb_page, 0);
+
+ unlock_page(req->wb_page);
+
+ dprintk("NFS: read done (%s/%Ld %d@%Ld)\n",
+ 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));
+ nfs_release_request(req);
+}
+
+int nfs_initiate_read(struct nfs_read_data *data, struct rpc_clnt *clnt,
+ const struct rpc_call_ops *call_ops)
+{
+ struct inode *inode = data->inode;
+ int swap_flags = IS_SWAPFILE(inode) ? NFS_RPC_SWAPFLAGS : 0;
+ 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 = {
+ .task = &data->task,
+ .rpc_client = clnt,
+ .rpc_message = &msg,
+ .callback_ops = call_ops,
+ .callback_data = data,
+ .workqueue = nfsiod_workqueue,
+ .flags = RPC_TASK_ASYNC | swap_flags,
+ };
+
+ /* Set up the initial task struct. */
+ NFS_PROTO(inode)->read_setup(data, &msg);
+
+ dprintk("NFS: %5u initiated read 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))
+ return PTR_ERR(task);
+ rpc_put_task(task);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(nfs_initiate_read);
+
+/*
+ * Set up the NFS read request struct
+ */
+static void nfs_read_rpcsetup(struct nfs_page *req, struct nfs_read_data *data,
+ unsigned int count, unsigned int offset)
+{
+ struct inode *inode = req->wb_context->dentry->d_inode;
+
+ data->req = req;
+ data->inode = inode;
+ data->cred = req->wb_context->cred;
+
+ data->args.fh = NFS_FH(inode);
+ data->args.offset = req_offset(req) + offset;
+ data->args.pgbase = req->wb_pgbase + offset;
+ data->args.pages = data->pagevec;
+ data->args.count = count;
+ data->args.context = get_nfs_open_context(req->wb_context);
+ data->args.lock_context = req->wb_lock_context;
+
+ data->res.fattr = &data->fattr;
+ data->res.count = count;
+ data->res.eof = 0;
+ nfs_fattr_init(&data->fattr);
+}
+
+static int nfs_do_read(struct nfs_read_data *data,
+ const struct rpc_call_ops *call_ops)
+{
+ struct inode *inode = data->args.context->dentry->d_inode;
+
+ return nfs_initiate_read(data, NFS_CLIENT(inode), call_ops);
+}
+
+static int
+nfs_do_multiple_reads(struct list_head *head,
+ const struct rpc_call_ops *call_ops)
+{
+ struct nfs_read_data *data;
+ int ret = 0;
+
+ while (!list_empty(head)) {
+ int ret2;
+
+ data = list_entry(head->next, struct nfs_read_data, list);
+ list_del_init(&data->list);
+
+ ret2 = nfs_do_read(data, call_ops);
+ if (ret == 0)
+ ret = ret2;
+ }
+ return ret;
+}
+
+static void
+nfs_async_read_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_readpage_release(req);
+ }
+}
+
+/*
+ * Generate multiple requests to fill a single page.
+ *
+ * We optimize to reduce the number of read operations on the wire. If we
+ * detect that we're reading a page, or an area of a page, that is past the
+ * end of file, we do not generate NFS read operations but just clear the
+ * parts of the page that would have come back zero from the server anyway.
+ *
+ * We rely on the cached value of i_size to make this determination; another
+ * client can fill pages on the server past our cached end-of-file, but we
+ * won't see the new data until our attribute cache is updated. This is more
+ * or less conventional NFS client behavior.
+ */
+static int nfs_pagein_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_read_data *data;
+ size_t rsize = desc->pg_bsize, nbytes;
+ unsigned int offset;
+ int requests = 0;
+ int ret = 0;
+
+ nfs_list_remove_request(req);
+
+ offset = 0;
+ nbytes = desc->pg_count;
+ do {
+ size_t len = min(nbytes,rsize);
+
+ data = nfs_readdata_alloc(1);
+ if (!data)
+ goto out_bad;
+ data->pagevec[0] = page;
+ nfs_read_rpcsetup(req, data, len, offset);
+ list_add(&data->list, res);
+ requests++;
+ nbytes -= len;
+ offset += len;
+ } while(nbytes != 0);
+ atomic_set(&req->wb_complete, requests);
+ desc->pg_rpc_callops = &nfs_read_partial_ops;
+ return ret;
+out_bad:
+ while (!list_empty(res)) {
+ data = list_entry(res->next, struct nfs_read_data, list);
+ list_del(&data->list);
+ nfs_readdata_release(data);
+ }
+ nfs_readpage_release(req);
+ return -ENOMEM;
+}
+
+static int nfs_pagein_one(struct nfs_pageio_descriptor *desc, struct list_head *res)
+{
+ struct nfs_page *req;
+ struct page **pages;
+ struct nfs_read_data *data;
+ struct list_head *head = &desc->pg_list;
+ int ret = 0;
+
+ data = nfs_readdata_alloc(nfs_page_array_len(desc->pg_base,
+ desc->pg_count));
+ if (!data) {
+ nfs_async_read_error(head);
+ 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);
+
+ nfs_read_rpcsetup(req, data, desc->pg_count, 0);
+ list_add(&data->list, res);
+ desc->pg_rpc_callops = &nfs_read_full_ops;
+out:
+ return ret;
+}
+
+int nfs_generic_pagein(struct nfs_pageio_descriptor *desc, struct list_head *head)
+{
+ if (desc->pg_bsize < PAGE_CACHE_SIZE)
+ return nfs_pagein_multi(desc, head);
+ return nfs_pagein_one(desc, head);
+}
+
+static int nfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc)
+{
+ LIST_HEAD(head);
+ int ret;
+
+ ret = nfs_generic_pagein(desc, &head);
+ if (ret == 0)
+ ret = nfs_do_multiple_reads(&head, desc->pg_rpc_callops);
+ return ret;
+}
+
+static const struct nfs_pageio_ops nfs_pageio_read_ops = {
+ .pg_test = nfs_generic_pg_test,
+ .pg_doio = nfs_generic_pg_readpages,
+};
+
+/*
+ * This is the callback from RPC telling us whether a reply was
+ * received or some error occurred (timeout or socket shutdown).
+ */
+int nfs_readpage_result(struct rpc_task *task, struct nfs_read_data *data)
+{
+ int status;
+
+ dprintk("NFS: %s: %5u, (status %d)\n", __func__, task->tk_pid,
+ task->tk_status);
+
+ status = NFS_PROTO(data->inode)->read_done(task, data);
+ if (status != 0)
+ return status;
+
+ nfs_add_stats(data->inode, NFSIOS_SERVERREADBYTES, data->res.count);
+
+ if (task->tk_status == -ESTALE) {
+ set_bit(NFS_INO_STALE, &NFS_I(data->inode)->flags);
+ nfs_mark_for_revalidate(data->inode);
+ }
+ return 0;
+}
+
+static void nfs_readpage_retry(struct rpc_task *task, struct nfs_read_data *data)
+{
+ struct nfs_readargs *argp = &data->args;
+ struct nfs_readres *resp = &data->res;
+
+ if (resp->eof || resp->count == argp->count)
+ return;
+
+ /* This is a short read! */
+ nfs_inc_stats(data->inode, NFSIOS_SHORTREAD);
+ /* Has the server at least made some progress? */
+ if (resp->count == 0)
+ return;
+
+ /* Yes, so retry the read at the end of the data */
+ data->mds_offset += resp->count;
+ argp->offset += resp->count;
+ argp->pgbase += resp->count;
+ argp->count -= resp->count;
+ rpc_restart_call_prepare(task);
+}
+
+/*
+ * Handle a read reply that fills part of a page.
+ */
+static void nfs_readpage_result_partial(struct rpc_task *task, void *calldata)
+{
+ struct nfs_read_data *data = calldata;
+
+ if (nfs_readpage_result(task, data) != 0)
+ return;
+ if (task->tk_status < 0)
+ return;
+
+ nfs_readpage_truncate_uninitialised_page(data);
+ nfs_readpage_retry(task, data);
+}
+
+static void nfs_readpage_release_partial(void *calldata)
+{
+ struct nfs_read_data *data = calldata;
+ struct nfs_page *req = data->req;
+ struct page *page = req->wb_page;
+ int status = data->task.tk_status;
+
+ if (status < 0)
+ set_bit(PG_PARTIAL_READ_FAILED, &req->wb_flags);
+
+ if (atomic_dec_and_test(&req->wb_complete)) {
+ if (!test_bit(PG_PARTIAL_READ_FAILED, &req->wb_flags))
+ SetPageUptodate(page);
+ nfs_readpage_release(req);
+ }
+ nfs_readdata_release(calldata);
+}
+
+void nfs_read_prepare(struct rpc_task *task, void *calldata)
+{
+ struct nfs_read_data *data = calldata;
+ NFS_PROTO(data->inode)->read_rpc_prepare(task, data);
+}
+
+static const struct rpc_call_ops nfs_read_partial_ops = {
+ .rpc_call_prepare = nfs_read_prepare,
+ .rpc_call_done = nfs_readpage_result_partial,
+ .rpc_release = nfs_readpage_release_partial,
+};
+
+static void nfs_readpage_set_pages_uptodate(struct nfs_read_data *data)
+{
+ unsigned int count = data->res.count;
+ unsigned int base = data->args.pgbase;
+ struct page **pages;
+
+ if (data->res.eof)
+ count = data->args.count;
+ if (unlikely(count == 0))
+ return;
+ pages = &data->args.pages[base >> PAGE_CACHE_SHIFT];
+ base &= ~PAGE_CACHE_MASK;
+ count += base;
+ for (;count >= PAGE_CACHE_SIZE; count -= PAGE_CACHE_SIZE, pages++)
+ SetPageUptodate(*pages);
+ if (count == 0)
+ return;
+ /* Was this a short read? */
+ if (data->res.eof || data->res.count == data->args.count)
+ SetPageUptodate(*pages);
+}
+
+/*
+ * This is the callback from RPC telling us whether a reply was
+ * received or some error occurred (timeout or socket shutdown).
+ */
+static void nfs_readpage_result_full(struct rpc_task *task, void *calldata)
+{
+ struct nfs_read_data *data = calldata;
+
+ if (nfs_readpage_result(task, data) != 0)
+ return;
+ if (task->tk_status < 0)
+ return;
+ /*
+ * Note: nfs_readpage_retry may change the values of
+ * data->args. In the multi-page case, we therefore need
+ * to ensure that we call nfs_readpage_set_pages_uptodate()
+ * first.
+ */
+ nfs_readpage_truncate_uninitialised_page(data);
+ nfs_readpage_set_pages_uptodate(data);
+ nfs_readpage_retry(task, data);
+}
+
+static void nfs_readpage_release_full(void *calldata)
+{
+ struct nfs_read_data *data = calldata;
+
+ while (!list_empty(&data->pages)) {
+ struct nfs_page *req = nfs_list_entry(data->pages.next);
+
+ nfs_list_remove_request(req);
+ nfs_readpage_release(req);
+ }
+ nfs_readdata_release(calldata);
+}
+
+static const struct rpc_call_ops nfs_read_full_ops = {
+ .rpc_call_prepare = nfs_read_prepare,
+ .rpc_call_done = nfs_readpage_result_full,
+ .rpc_release = nfs_readpage_release_full,
+};
+
+/*
+ * Read a page over NFS.
+ * We read the page synchronously in the following case:
+ * - The error flag is set for this page. This happens only when a
+ * previous async read operation failed.
+ */
+int nfs_readpage(struct file *file, struct page *page)
+{
+ struct nfs_open_context *ctx;
+ struct inode *inode = page->mapping->host;
+ int error;
+
+ dprintk("NFS: nfs_readpage (%p %ld@%lu)\n",
+ page, PAGE_CACHE_SIZE, page->index);
+ nfs_inc_stats(inode, NFSIOS_VFSREADPAGE);
+ nfs_add_stats(inode, NFSIOS_READPAGES, 1);
+
+ /*
+ * Try to flush any pending writes to the file..
+ *
+ * NOTE! Because we own the page lock, there cannot
+ * be any new pending writes generated at this point
+ * for this page (other pages can be written to).
+ */
+ error = nfs_wb_page(inode, page);
+ if (error)
+ goto out_unlock;
+ if (PageUptodate(page))
+ goto out_unlock;
+
+ error = -ESTALE;
+ if (NFS_STALE(inode))
+ goto out_unlock;
+
+ if (file == NULL) {
+ error = -EBADF;
+ ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
+ if (ctx == NULL)
+ goto out_unlock;
+ } else
+ ctx = get_nfs_open_context(nfs_file_open_context(file));
+
+ if (!IS_SYNC(inode)) {
+ error = nfs_readpage_from_fscache(ctx, inode, page);
+ if (error == 0)
+ goto out;
+ }
+
+ error = nfs_readpage_async(ctx, inode, page);
+
+out:
+ put_nfs_open_context(ctx);
+ return error;
+out_unlock:
+ unlock_page(page);
+ return error;
+}
+
+struct nfs_readdesc {
+ struct nfs_pageio_descriptor *pgio;
+ struct nfs_open_context *ctx;
+};
+
+static int
+readpage_async_filler(void *data, struct page *page)
+{
+ struct nfs_readdesc *desc = (struct nfs_readdesc *)data;
+ struct inode *inode = page->mapping->host;
+ struct nfs_page *new;
+ unsigned int len;
+ int error;
+
+ len = nfs_page_length(page);
+ if (len == 0)
+ return nfs_return_empty_page(page);
+
+ new = nfs_create_request(desc->ctx, inode, page, 0, len);
+ if (IS_ERR(new))
+ goto out_error;
+
+ if (len < PAGE_CACHE_SIZE)
+ zero_user_segment(page, len, PAGE_CACHE_SIZE);
+ if (!nfs_pageio_add_request(desc->pgio, new)) {
+ error = desc->pgio->pg_error;
+ goto out_unlock;
+ }
+ return 0;
+out_error:
+ error = PTR_ERR(new);
+out_unlock:
+ unlock_page(page);
+ return error;
+}
+
+int nfs_readpages(struct file *filp, struct address_space *mapping,
+ struct list_head *pages, unsigned nr_pages)
+{
+ struct nfs_pageio_descriptor pgio;
+ struct nfs_readdesc desc = {
+ .pgio = &pgio,
+ };
+ struct inode *inode = mapping->host;
+ unsigned long npages;
+ int ret = -ESTALE;
+
+ dprintk("NFS: nfs_readpages (%s/%Ld %d)\n",
+ inode->i_sb->s_id,
+ (long long)NFS_FILEID(inode),
+ nr_pages);
+ nfs_inc_stats(inode, NFSIOS_VFSREADPAGES);
+
+ if (NFS_STALE(inode))
+ goto out;
+
+ if (filp == NULL) {
+ desc.ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
+ if (desc.ctx == NULL)
+ return -EBADF;
+ } else
+ desc.ctx = get_nfs_open_context(nfs_file_open_context(filp));
+
+ /* attempt to read as many of the pages as possible from the cache
+ * - this returns -ENOBUFS immediately if the cookie is negative
+ */
+ ret = nfs_readpages_from_fscache(desc.ctx, inode, mapping,
+ pages, &nr_pages);
+ if (ret == 0)
+ goto read_complete; /* all pages were read */
+
+ nfs_pageio_init_read(&pgio, inode);
+
+ ret = read_cache_pages(mapping, pages, readpage_async_filler, &desc);
+
+ nfs_pageio_complete(&pgio);
+ npages = (pgio.pg_bytes_written + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+ nfs_add_stats(inode, NFSIOS_READPAGES, npages);
+read_complete:
+ put_nfs_open_context(desc.ctx);
+out:
+ return ret;
+}
+
+int __init nfs_init_readpagecache(void)
+{
+ nfs_rdata_cachep = kmem_cache_create("nfs_read_data",
+ sizeof(struct nfs_read_data),
+ 0, SLAB_HWCACHE_ALIGN,
+ NULL);
+ if (nfs_rdata_cachep == NULL)
+ return -ENOMEM;
+
+ return 0;
+}
+
+void nfs_destroy_readpagecache(void)
+{
+ kmem_cache_destroy(nfs_rdata_cachep);
+}