[Feature]add MT2731_MP2_MR2_SVN388 baseline version
Change-Id: Ief04314834b31e27effab435d3ca8ba33b499059
diff --git a/src/kernel/linux/v4.14/fs/nfs/dir.c b/src/kernel/linux/v4.14/fs/nfs/dir.c
new file mode 100644
index 0000000..7dba259
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/nfs/dir.c
@@ -0,0 +1,2614 @@
+/*
+ * linux/fs/nfs/dir.c
+ *
+ * Copyright (C) 1992 Rick Sladkey
+ *
+ * nfs directory handling functions
+ *
+ * 10 Apr 1996 Added silly rename for unlink --okir
+ * 28 Sep 1996 Improved directory cache --okir
+ * 23 Aug 1997 Claus Heine claus@momo.math.rwth-aachen.de
+ * Re-implemented silly rename for unlink, newly implemented
+ * silly rename for nfs_rename() following the suggestions
+ * of Olaf Kirch (okir) found in this file.
+ * Following Linus comments on my original hack, this version
+ * depends only on the dcache stuff and doesn't touch the inode
+ * layer (iput() and friends).
+ * 6 Jun 1999 Cache readdir lookups in the page cache. -DaveM
+ */
+
+#include <linux/module.h>
+#include <linux/time.h>
+#include <linux/errno.h>
+#include <linux/stat.h>
+#include <linux/fcntl.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/nfs_fs.h>
+#include <linux/nfs_mount.h>
+#include <linux/pagemap.h>
+#include <linux/pagevec.h>
+#include <linux/namei.h>
+#include <linux/mount.h>
+#include <linux/swap.h>
+#include <linux/sched.h>
+#include <linux/kmemleak.h>
+#include <linux/xattr.h>
+
+#include "delegation.h"
+#include "iostat.h"
+#include "internal.h"
+#include "fscache.h"
+
+#include "nfstrace.h"
+
+/* #define NFS_DEBUG_VERBOSE 1 */
+
+static int nfs_opendir(struct inode *, struct file *);
+static int nfs_closedir(struct inode *, struct file *);
+static int nfs_readdir(struct file *, struct dir_context *);
+static int nfs_fsync_dir(struct file *, loff_t, loff_t, int);
+static loff_t nfs_llseek_dir(struct file *, loff_t, int);
+static void nfs_readdir_clear_array(struct page*);
+
+const struct file_operations nfs_dir_operations = {
+ .llseek = nfs_llseek_dir,
+ .read = generic_read_dir,
+ .iterate = nfs_readdir,
+ .open = nfs_opendir,
+ .release = nfs_closedir,
+ .fsync = nfs_fsync_dir,
+};
+
+const struct address_space_operations nfs_dir_aops = {
+ .freepage = nfs_readdir_clear_array,
+};
+
+static struct nfs_open_dir_context *alloc_nfs_open_dir_context(struct inode *dir, struct rpc_cred *cred)
+{
+ struct nfs_inode *nfsi = NFS_I(dir);
+ struct nfs_open_dir_context *ctx;
+ ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
+ if (ctx != NULL) {
+ ctx->duped = 0;
+ ctx->attr_gencount = nfsi->attr_gencount;
+ ctx->dir_cookie = 0;
+ ctx->dup_cookie = 0;
+ ctx->cred = get_rpccred(cred);
+ spin_lock(&dir->i_lock);
+ list_add(&ctx->list, &nfsi->open_files);
+ spin_unlock(&dir->i_lock);
+ return ctx;
+ }
+ return ERR_PTR(-ENOMEM);
+}
+
+static void put_nfs_open_dir_context(struct inode *dir, struct nfs_open_dir_context *ctx)
+{
+ spin_lock(&dir->i_lock);
+ list_del(&ctx->list);
+ spin_unlock(&dir->i_lock);
+ put_rpccred(ctx->cred);
+ kfree(ctx);
+}
+
+/*
+ * Open file
+ */
+static int
+nfs_opendir(struct inode *inode, struct file *filp)
+{
+ int res = 0;
+ struct nfs_open_dir_context *ctx;
+ struct rpc_cred *cred;
+
+ dfprintk(FILE, "NFS: open dir(%pD2)\n", filp);
+
+ nfs_inc_stats(inode, NFSIOS_VFSOPEN);
+
+ cred = rpc_lookup_cred();
+ if (IS_ERR(cred))
+ return PTR_ERR(cred);
+ ctx = alloc_nfs_open_dir_context(inode, cred);
+ if (IS_ERR(ctx)) {
+ res = PTR_ERR(ctx);
+ goto out;
+ }
+ filp->private_data = ctx;
+ if (filp->f_path.dentry == filp->f_path.mnt->mnt_root) {
+ /* This is a mountpoint, so d_revalidate will never
+ * have been called, so we need to refresh the
+ * inode (for close-open consistency) ourselves.
+ */
+ __nfs_revalidate_inode(NFS_SERVER(inode), inode);
+ }
+out:
+ put_rpccred(cred);
+ return res;
+}
+
+static int
+nfs_closedir(struct inode *inode, struct file *filp)
+{
+ put_nfs_open_dir_context(file_inode(filp), filp->private_data);
+ return 0;
+}
+
+struct nfs_cache_array_entry {
+ u64 cookie;
+ u64 ino;
+ struct qstr string;
+ unsigned char d_type;
+};
+
+struct nfs_cache_array {
+ int size;
+ int eof_index;
+ u64 last_cookie;
+ struct nfs_cache_array_entry array[0];
+};
+
+typedef int (*decode_dirent_t)(struct xdr_stream *, struct nfs_entry *, bool);
+typedef struct {
+ struct file *file;
+ struct page *page;
+ struct dir_context *ctx;
+ unsigned long page_index;
+ u64 *dir_cookie;
+ u64 last_cookie;
+ loff_t current_index;
+ decode_dirent_t decode;
+
+ unsigned long timestamp;
+ unsigned long gencount;
+ unsigned int cache_entry_index;
+ bool plus;
+ bool eof;
+} nfs_readdir_descriptor_t;
+
+static
+void nfs_readdir_init_array(struct page *page)
+{
+ struct nfs_cache_array *array;
+
+ array = kmap_atomic(page);
+ memset(array, 0, sizeof(struct nfs_cache_array));
+ array->eof_index = -1;
+ kunmap_atomic(array);
+}
+
+/*
+ * we are freeing strings created by nfs_add_to_readdir_array()
+ */
+static
+void nfs_readdir_clear_array(struct page *page)
+{
+ struct nfs_cache_array *array;
+ int i;
+
+ array = kmap_atomic(page);
+ for (i = 0; i < array->size; i++)
+ kfree(array->array[i].string.name);
+ array->size = 0;
+ kunmap_atomic(array);
+}
+
+/*
+ * the caller is responsible for freeing qstr.name
+ * when called by nfs_readdir_add_to_array, the strings will be freed in
+ * nfs_clear_readdir_array()
+ */
+static
+int nfs_readdir_make_qstr(struct qstr *string, const char *name, unsigned int len)
+{
+ string->len = len;
+ string->name = kmemdup(name, len, GFP_KERNEL);
+ if (string->name == NULL)
+ return -ENOMEM;
+ /*
+ * Avoid a kmemleak false positive. The pointer to the name is stored
+ * in a page cache page which kmemleak does not scan.
+ */
+ kmemleak_not_leak(string->name);
+ string->hash = full_name_hash(NULL, name, len);
+ return 0;
+}
+
+static
+int nfs_readdir_add_to_array(struct nfs_entry *entry, struct page *page)
+{
+ struct nfs_cache_array *array = kmap(page);
+ struct nfs_cache_array_entry *cache_entry;
+ int ret;
+
+ cache_entry = &array->array[array->size];
+
+ /* Check that this entry lies within the page bounds */
+ ret = -ENOSPC;
+ if ((char *)&cache_entry[1] - (char *)page_address(page) > PAGE_SIZE)
+ goto out;
+
+ cache_entry->cookie = entry->prev_cookie;
+ cache_entry->ino = entry->ino;
+ cache_entry->d_type = entry->d_type;
+ ret = nfs_readdir_make_qstr(&cache_entry->string, entry->name, entry->len);
+ if (ret)
+ goto out;
+ array->last_cookie = entry->cookie;
+ array->size++;
+ if (entry->eof != 0)
+ array->eof_index = array->size;
+out:
+ kunmap(page);
+ return ret;
+}
+
+static
+int nfs_readdir_search_for_pos(struct nfs_cache_array *array, nfs_readdir_descriptor_t *desc)
+{
+ loff_t diff = desc->ctx->pos - desc->current_index;
+ unsigned int index;
+
+ if (diff < 0)
+ goto out_eof;
+ if (diff >= array->size) {
+ if (array->eof_index >= 0)
+ goto out_eof;
+ return -EAGAIN;
+ }
+
+ index = (unsigned int)diff;
+ *desc->dir_cookie = array->array[index].cookie;
+ desc->cache_entry_index = index;
+ return 0;
+out_eof:
+ desc->eof = 1;
+ return -EBADCOOKIE;
+}
+
+static bool
+nfs_readdir_inode_mapping_valid(struct nfs_inode *nfsi)
+{
+ if (nfsi->cache_validity & (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA))
+ return false;
+ smp_rmb();
+ return !test_bit(NFS_INO_INVALIDATING, &nfsi->flags);
+}
+
+static
+int nfs_readdir_search_for_cookie(struct nfs_cache_array *array, nfs_readdir_descriptor_t *desc)
+{
+ int i;
+ loff_t new_pos;
+ int status = -EAGAIN;
+
+ for (i = 0; i < array->size; i++) {
+ if (array->array[i].cookie == *desc->dir_cookie) {
+ struct nfs_inode *nfsi = NFS_I(file_inode(desc->file));
+ struct nfs_open_dir_context *ctx = desc->file->private_data;
+
+ new_pos = desc->current_index + i;
+ if (ctx->attr_gencount != nfsi->attr_gencount ||
+ !nfs_readdir_inode_mapping_valid(nfsi)) {
+ ctx->duped = 0;
+ ctx->attr_gencount = nfsi->attr_gencount;
+ } else if (new_pos < desc->ctx->pos) {
+ if (ctx->duped > 0
+ && ctx->dup_cookie == *desc->dir_cookie) {
+ if (printk_ratelimit()) {
+ pr_notice("NFS: directory %pD2 contains a readdir loop."
+ "Please contact your server vendor. "
+ "The file: %.*s has duplicate cookie %llu\n",
+ desc->file, array->array[i].string.len,
+ array->array[i].string.name, *desc->dir_cookie);
+ }
+ status = -ELOOP;
+ goto out;
+ }
+ ctx->dup_cookie = *desc->dir_cookie;
+ ctx->duped = -1;
+ }
+ desc->ctx->pos = new_pos;
+ desc->cache_entry_index = i;
+ return 0;
+ }
+ }
+ if (array->eof_index >= 0) {
+ status = -EBADCOOKIE;
+ if (*desc->dir_cookie == array->last_cookie)
+ desc->eof = 1;
+ }
+out:
+ return status;
+}
+
+static
+int nfs_readdir_search_array(nfs_readdir_descriptor_t *desc)
+{
+ struct nfs_cache_array *array;
+ int status;
+
+ array = kmap(desc->page);
+
+ if (*desc->dir_cookie == 0)
+ status = nfs_readdir_search_for_pos(array, desc);
+ else
+ status = nfs_readdir_search_for_cookie(array, desc);
+
+ if (status == -EAGAIN) {
+ desc->last_cookie = array->last_cookie;
+ desc->current_index += array->size;
+ desc->page_index++;
+ }
+ kunmap(desc->page);
+ return status;
+}
+
+/* Fill a page with xdr information before transferring to the cache page */
+static
+int nfs_readdir_xdr_filler(struct page **pages, nfs_readdir_descriptor_t *desc,
+ struct nfs_entry *entry, struct file *file, struct inode *inode)
+{
+ struct nfs_open_dir_context *ctx = file->private_data;
+ struct rpc_cred *cred = ctx->cred;
+ unsigned long timestamp, gencount;
+ int error;
+
+ again:
+ timestamp = jiffies;
+ gencount = nfs_inc_attr_generation_counter();
+ error = NFS_PROTO(inode)->readdir(file_dentry(file), cred, entry->cookie, pages,
+ NFS_SERVER(inode)->dtsize, desc->plus);
+ if (error < 0) {
+ /* We requested READDIRPLUS, but the server doesn't grok it */
+ if (error == -ENOTSUPP && desc->plus) {
+ NFS_SERVER(inode)->caps &= ~NFS_CAP_READDIRPLUS;
+ clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags);
+ desc->plus = false;
+ goto again;
+ }
+ goto error;
+ }
+ desc->timestamp = timestamp;
+ desc->gencount = gencount;
+error:
+ return error;
+}
+
+static int xdr_decode(nfs_readdir_descriptor_t *desc,
+ struct nfs_entry *entry, struct xdr_stream *xdr)
+{
+ int error;
+
+ error = desc->decode(xdr, entry, desc->plus);
+ if (error)
+ return error;
+ entry->fattr->time_start = desc->timestamp;
+ entry->fattr->gencount = desc->gencount;
+ return 0;
+}
+
+/* Match file and dirent using either filehandle or fileid
+ * Note: caller is responsible for checking the fsid
+ */
+static
+int nfs_same_file(struct dentry *dentry, struct nfs_entry *entry)
+{
+ struct inode *inode;
+ struct nfs_inode *nfsi;
+
+ if (d_really_is_negative(dentry))
+ return 0;
+
+ inode = d_inode(dentry);
+ if (is_bad_inode(inode) || NFS_STALE(inode))
+ return 0;
+
+ nfsi = NFS_I(inode);
+ if (entry->fattr->fileid != nfsi->fileid)
+ return 0;
+ if (entry->fh->size && nfs_compare_fh(entry->fh, &nfsi->fh) != 0)
+ return 0;
+ return 1;
+}
+
+static
+bool nfs_use_readdirplus(struct inode *dir, struct dir_context *ctx)
+{
+ if (!nfs_server_capable(dir, NFS_CAP_READDIRPLUS))
+ return false;
+ if (test_and_clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(dir)->flags))
+ return true;
+ if (ctx->pos == 0)
+ return true;
+ return false;
+}
+
+/*
+ * This function is called by the lookup and getattr code to request the
+ * use of readdirplus to accelerate any future lookups in the same
+ * directory.
+ */
+void nfs_advise_use_readdirplus(struct inode *dir)
+{
+ struct nfs_inode *nfsi = NFS_I(dir);
+
+ if (nfs_server_capable(dir, NFS_CAP_READDIRPLUS) &&
+ !list_empty(&nfsi->open_files))
+ set_bit(NFS_INO_ADVISE_RDPLUS, &nfsi->flags);
+}
+
+/*
+ * This function is mainly for use by nfs_getattr().
+ *
+ * If this is an 'ls -l', we want to force use of readdirplus.
+ * Do this by checking if there is an active file descriptor
+ * and calling nfs_advise_use_readdirplus, then forcing a
+ * cache flush.
+ */
+void nfs_force_use_readdirplus(struct inode *dir)
+{
+ struct nfs_inode *nfsi = NFS_I(dir);
+
+ if (nfs_server_capable(dir, NFS_CAP_READDIRPLUS) &&
+ !list_empty(&nfsi->open_files)) {
+ set_bit(NFS_INO_ADVISE_RDPLUS, &nfsi->flags);
+ invalidate_mapping_pages(dir->i_mapping, 0, -1);
+ }
+}
+
+static
+void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry)
+{
+ struct qstr filename = QSTR_INIT(entry->name, entry->len);
+ DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
+ struct dentry *dentry;
+ struct dentry *alias;
+ struct inode *dir = d_inode(parent);
+ struct inode *inode;
+ int status;
+
+ if (!(entry->fattr->valid & NFS_ATTR_FATTR_FILEID))
+ return;
+ if (!(entry->fattr->valid & NFS_ATTR_FATTR_FSID))
+ return;
+ if (filename.len == 0)
+ return;
+ /* Validate that the name doesn't contain any illegal '\0' */
+ if (strnlen(filename.name, filename.len) != filename.len)
+ return;
+ /* ...or '/' */
+ if (strnchr(filename.name, filename.len, '/'))
+ return;
+ if (filename.name[0] == '.') {
+ if (filename.len == 1)
+ return;
+ if (filename.len == 2 && filename.name[1] == '.')
+ return;
+ }
+ filename.hash = full_name_hash(parent, filename.name, filename.len);
+
+ dentry = d_lookup(parent, &filename);
+again:
+ if (!dentry) {
+ dentry = d_alloc_parallel(parent, &filename, &wq);
+ if (IS_ERR(dentry))
+ return;
+ }
+ if (!d_in_lookup(dentry)) {
+ /* Is there a mountpoint here? If so, just exit */
+ if (!nfs_fsid_equal(&NFS_SB(dentry->d_sb)->fsid,
+ &entry->fattr->fsid))
+ goto out;
+ if (nfs_same_file(dentry, entry)) {
+ if (!entry->fh->size)
+ goto out;
+ nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
+ status = nfs_refresh_inode(d_inode(dentry), entry->fattr);
+ if (!status)
+ nfs_setsecurity(d_inode(dentry), entry->fattr, entry->label);
+ goto out;
+ } else {
+ d_invalidate(dentry);
+ dput(dentry);
+ dentry = NULL;
+ goto again;
+ }
+ }
+ if (!entry->fh->size) {
+ d_lookup_done(dentry);
+ goto out;
+ }
+
+ inode = nfs_fhget(dentry->d_sb, entry->fh, entry->fattr, entry->label);
+ alias = d_splice_alias(inode, dentry);
+ d_lookup_done(dentry);
+ if (alias) {
+ if (IS_ERR(alias))
+ goto out;
+ dput(dentry);
+ dentry = alias;
+ }
+ nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
+out:
+ dput(dentry);
+}
+
+/* Perform conversion from xdr to cache array */
+static
+int nfs_readdir_page_filler(nfs_readdir_descriptor_t *desc, struct nfs_entry *entry,
+ struct page **xdr_pages, struct page *page, unsigned int buflen)
+{
+ struct xdr_stream stream;
+ struct xdr_buf buf;
+ struct page *scratch;
+ struct nfs_cache_array *array;
+ unsigned int count = 0;
+ int status;
+
+ scratch = alloc_page(GFP_KERNEL);
+ if (scratch == NULL)
+ return -ENOMEM;
+
+ if (buflen == 0)
+ goto out_nopages;
+
+ xdr_init_decode_pages(&stream, &buf, xdr_pages, buflen);
+ xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
+
+ do {
+ status = xdr_decode(desc, entry, &stream);
+ if (status != 0) {
+ if (status == -EAGAIN)
+ status = 0;
+ break;
+ }
+
+ count++;
+
+ if (desc->plus)
+ nfs_prime_dcache(file_dentry(desc->file), entry);
+
+ status = nfs_readdir_add_to_array(entry, page);
+ if (status != 0)
+ break;
+ } while (!entry->eof);
+
+out_nopages:
+ if (count == 0 || (status == -EBADCOOKIE && entry->eof != 0)) {
+ array = kmap(page);
+ array->eof_index = array->size;
+ status = 0;
+ kunmap(page);
+ }
+
+ put_page(scratch);
+ return status;
+}
+
+static
+void nfs_readdir_free_pages(struct page **pages, unsigned int npages)
+{
+ unsigned int i;
+ for (i = 0; i < npages; i++)
+ put_page(pages[i]);
+}
+
+/*
+ * nfs_readdir_large_page will allocate pages that must be freed with a call
+ * to nfs_readdir_free_pagearray
+ */
+static
+int nfs_readdir_alloc_pages(struct page **pages, unsigned int npages)
+{
+ unsigned int i;
+
+ for (i = 0; i < npages; i++) {
+ struct page *page = alloc_page(GFP_KERNEL);
+ if (page == NULL)
+ goto out_freepages;
+ pages[i] = page;
+ }
+ return 0;
+
+out_freepages:
+ nfs_readdir_free_pages(pages, i);
+ return -ENOMEM;
+}
+
+static
+int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page, struct inode *inode)
+{
+ struct page *pages[NFS_MAX_READDIR_PAGES];
+ struct nfs_entry entry;
+ struct file *file = desc->file;
+ struct nfs_cache_array *array;
+ int status = -ENOMEM;
+ unsigned int array_size = ARRAY_SIZE(pages);
+
+ nfs_readdir_init_array(page);
+
+ entry.prev_cookie = 0;
+ entry.cookie = desc->last_cookie;
+ entry.eof = 0;
+ entry.fh = nfs_alloc_fhandle();
+ entry.fattr = nfs_alloc_fattr();
+ entry.server = NFS_SERVER(inode);
+ if (entry.fh == NULL || entry.fattr == NULL)
+ goto out;
+
+ entry.label = nfs4_label_alloc(NFS_SERVER(inode), GFP_NOWAIT);
+ if (IS_ERR(entry.label)) {
+ status = PTR_ERR(entry.label);
+ goto out;
+ }
+
+ array = kmap(page);
+
+ status = nfs_readdir_alloc_pages(pages, array_size);
+ if (status < 0)
+ goto out_release_array;
+ do {
+ unsigned int pglen;
+ status = nfs_readdir_xdr_filler(pages, desc, &entry, file, inode);
+
+ if (status < 0)
+ break;
+ pglen = status;
+ status = nfs_readdir_page_filler(desc, &entry, pages, page, pglen);
+ if (status < 0) {
+ if (status == -ENOSPC)
+ status = 0;
+ break;
+ }
+ } while (array->eof_index < 0);
+
+ nfs_readdir_free_pages(pages, array_size);
+out_release_array:
+ kunmap(page);
+ nfs4_label_free(entry.label);
+out:
+ nfs_free_fattr(entry.fattr);
+ nfs_free_fhandle(entry.fh);
+ return status;
+}
+
+/*
+ * Now we cache directories properly, by converting xdr information
+ * to an array that can be used for lookups later. This results in
+ * fewer cache pages, since we can store more information on each page.
+ * We only need to convert from xdr once so future lookups are much simpler
+ */
+static
+int nfs_readdir_filler(struct file *file, struct page* page)
+{
+ nfs_readdir_descriptor_t *desc = (nfs_readdir_descriptor_t *)file;
+ struct inode *inode = file_inode(desc->file);
+ int ret;
+
+ ret = nfs_readdir_xdr_to_array(desc, page, inode);
+ if (ret < 0)
+ goto error;
+ SetPageUptodate(page);
+
+ if (invalidate_inode_pages2_range(inode->i_mapping, page->index + 1, -1) < 0) {
+ /* Should never happen */
+ nfs_zap_mapping(inode, inode->i_mapping);
+ }
+ unlock_page(page);
+ return 0;
+ error:
+ nfs_readdir_clear_array(page);
+ unlock_page(page);
+ return ret;
+}
+
+static
+void cache_page_release(nfs_readdir_descriptor_t *desc)
+{
+ put_page(desc->page);
+ desc->page = NULL;
+}
+
+static
+struct page *get_cache_page(nfs_readdir_descriptor_t *desc)
+{
+ return read_cache_page(desc->file->f_mapping,
+ desc->page_index, nfs_readdir_filler, desc);
+}
+
+/*
+ * Returns 0 if desc->dir_cookie was found on page desc->page_index
+ * and locks the page to prevent removal from the page cache.
+ */
+static
+int find_and_lock_cache_page(nfs_readdir_descriptor_t *desc)
+{
+ int res;
+
+ desc->page = get_cache_page(desc);
+ if (IS_ERR(desc->page))
+ return PTR_ERR(desc->page);
+ res = lock_page_killable(desc->page);
+ if (res != 0)
+ goto error;
+ res = -EAGAIN;
+ if (desc->page->mapping != NULL) {
+ res = nfs_readdir_search_array(desc);
+ if (res == 0)
+ return 0;
+ }
+ unlock_page(desc->page);
+error:
+ cache_page_release(desc);
+ return res;
+}
+
+/* Search for desc->dir_cookie from the beginning of the page cache */
+static inline
+int readdir_search_pagecache(nfs_readdir_descriptor_t *desc)
+{
+ int res;
+
+ if (desc->page_index == 0) {
+ desc->current_index = 0;
+ desc->last_cookie = 0;
+ }
+ do {
+ res = find_and_lock_cache_page(desc);
+ } while (res == -EAGAIN);
+ return res;
+}
+
+/*
+ * Once we've found the start of the dirent within a page: fill 'er up...
+ */
+static
+int nfs_do_filldir(nfs_readdir_descriptor_t *desc)
+{
+ struct file *file = desc->file;
+ int i = 0;
+ int res = 0;
+ struct nfs_cache_array *array = NULL;
+ struct nfs_open_dir_context *ctx = file->private_data;
+
+ array = kmap(desc->page);
+ for (i = desc->cache_entry_index; i < array->size; i++) {
+ struct nfs_cache_array_entry *ent;
+
+ ent = &array->array[i];
+ if (!dir_emit(desc->ctx, ent->string.name, ent->string.len,
+ nfs_compat_user_ino64(ent->ino), ent->d_type)) {
+ desc->eof = 1;
+ break;
+ }
+ desc->ctx->pos++;
+ if (i < (array->size-1))
+ *desc->dir_cookie = array->array[i+1].cookie;
+ else
+ *desc->dir_cookie = array->last_cookie;
+ if (ctx->duped != 0)
+ ctx->duped = 1;
+ }
+ if (array->eof_index >= 0)
+ desc->eof = 1;
+
+ kunmap(desc->page);
+ dfprintk(DIRCACHE, "NFS: nfs_do_filldir() filling ended @ cookie %Lu; returning = %d\n",
+ (unsigned long long)*desc->dir_cookie, res);
+ return res;
+}
+
+/*
+ * If we cannot find a cookie in our cache, we suspect that this is
+ * because it points to a deleted file, so we ask the server to return
+ * whatever it thinks is the next entry. We then feed this to filldir.
+ * If all goes well, we should then be able to find our way round the
+ * cache on the next call to readdir_search_pagecache();
+ *
+ * NOTE: we cannot add the anonymous page to the pagecache because
+ * the data it contains might not be page aligned. Besides,
+ * we should already have a complete representation of the
+ * directory in the page cache by the time we get here.
+ */
+static inline
+int uncached_readdir(nfs_readdir_descriptor_t *desc)
+{
+ struct page *page = NULL;
+ int status;
+ struct inode *inode = file_inode(desc->file);
+ struct nfs_open_dir_context *ctx = desc->file->private_data;
+
+ dfprintk(DIRCACHE, "NFS: uncached_readdir() searching for cookie %Lu\n",
+ (unsigned long long)*desc->dir_cookie);
+
+ page = alloc_page(GFP_HIGHUSER);
+ if (!page) {
+ status = -ENOMEM;
+ goto out;
+ }
+
+ desc->page_index = 0;
+ desc->last_cookie = *desc->dir_cookie;
+ desc->page = page;
+ ctx->duped = 0;
+
+ status = nfs_readdir_xdr_to_array(desc, page, inode);
+ if (status < 0)
+ goto out_release;
+
+ status = nfs_do_filldir(desc);
+
+ out_release:
+ nfs_readdir_clear_array(desc->page);
+ cache_page_release(desc);
+ out:
+ dfprintk(DIRCACHE, "NFS: %s: returns %d\n",
+ __func__, status);
+ return status;
+}
+
+/* The file offset position represents the dirent entry number. A
+ last cookie cache takes care of the common case of reading the
+ whole directory.
+ */
+static int nfs_readdir(struct file *file, struct dir_context *ctx)
+{
+ struct dentry *dentry = file_dentry(file);
+ struct inode *inode = d_inode(dentry);
+ nfs_readdir_descriptor_t my_desc,
+ *desc = &my_desc;
+ struct nfs_open_dir_context *dir_ctx = file->private_data;
+ int res = 0;
+
+ dfprintk(FILE, "NFS: readdir(%pD2) starting at cookie %llu\n",
+ file, (long long)ctx->pos);
+ nfs_inc_stats(inode, NFSIOS_VFSGETDENTS);
+
+ /*
+ * ctx->pos points to the dirent entry number.
+ * *desc->dir_cookie has the cookie for the next entry. We have
+ * to either find the entry with the appropriate number or
+ * revalidate the cookie.
+ */
+ memset(desc, 0, sizeof(*desc));
+
+ desc->file = file;
+ desc->ctx = ctx;
+ desc->dir_cookie = &dir_ctx->dir_cookie;
+ desc->decode = NFS_PROTO(inode)->decode_dirent;
+ desc->plus = nfs_use_readdirplus(inode, ctx);
+
+ if (ctx->pos == 0 || nfs_attribute_cache_expired(inode))
+ res = nfs_revalidate_mapping(inode, file->f_mapping);
+ if (res < 0)
+ goto out;
+
+ do {
+ res = readdir_search_pagecache(desc);
+
+ if (res == -EBADCOOKIE) {
+ res = 0;
+ /* This means either end of directory */
+ if (*desc->dir_cookie && desc->eof == 0) {
+ /* Or that the server has 'lost' a cookie */
+ res = uncached_readdir(desc);
+ if (res == 0)
+ continue;
+ }
+ break;
+ }
+ if (res == -ETOOSMALL && desc->plus) {
+ clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags);
+ nfs_zap_caches(inode);
+ desc->page_index = 0;
+ desc->plus = false;
+ desc->eof = false;
+ continue;
+ }
+ if (res < 0)
+ break;
+
+ res = nfs_do_filldir(desc);
+ unlock_page(desc->page);
+ cache_page_release(desc);
+ if (res < 0)
+ break;
+ } while (!desc->eof);
+out:
+ if (res > 0)
+ res = 0;
+ dfprintk(FILE, "NFS: readdir(%pD2) returns %d\n", file, res);
+ return res;
+}
+
+static loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int whence)
+{
+ struct inode *inode = file_inode(filp);
+ struct nfs_open_dir_context *dir_ctx = filp->private_data;
+
+ dfprintk(FILE, "NFS: llseek dir(%pD2, %lld, %d)\n",
+ filp, offset, whence);
+
+ inode_lock(inode);
+ switch (whence) {
+ case 1:
+ offset += filp->f_pos;
+ case 0:
+ if (offset >= 0)
+ break;
+ default:
+ offset = -EINVAL;
+ goto out;
+ }
+ if (offset != filp->f_pos) {
+ filp->f_pos = offset;
+ dir_ctx->dir_cookie = 0;
+ dir_ctx->duped = 0;
+ }
+out:
+ inode_unlock(inode);
+ return offset;
+}
+
+/*
+ * All directory operations under NFS are synchronous, so fsync()
+ * is a dummy operation.
+ */
+static int nfs_fsync_dir(struct file *filp, loff_t start, loff_t end,
+ int datasync)
+{
+ struct inode *inode = file_inode(filp);
+
+ dfprintk(FILE, "NFS: fsync dir(%pD2) datasync %d\n", filp, datasync);
+
+ inode_lock(inode);
+ nfs_inc_stats(inode, NFSIOS_VFSFSYNC);
+ inode_unlock(inode);
+ return 0;
+}
+
+/**
+ * nfs_force_lookup_revalidate - Mark the directory as having changed
+ * @dir - pointer to directory inode
+ *
+ * This forces the revalidation code in nfs_lookup_revalidate() to do a
+ * full lookup on all child dentries of 'dir' whenever a change occurs
+ * on the server that might have invalidated our dcache.
+ *
+ * The caller should be holding dir->i_lock
+ */
+void nfs_force_lookup_revalidate(struct inode *dir)
+{
+ NFS_I(dir)->cache_change_attribute++;
+}
+EXPORT_SYMBOL_GPL(nfs_force_lookup_revalidate);
+
+/*
+ * A check for whether or not the parent directory has changed.
+ * In the case it has, we assume that the dentries are untrustworthy
+ * and may need to be looked up again.
+ * If rcu_walk prevents us from performing a full check, return 0.
+ */
+static int nfs_check_verifier(struct inode *dir, struct dentry *dentry,
+ int rcu_walk)
+{
+ if (IS_ROOT(dentry))
+ return 1;
+ if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
+ return 0;
+ if (!nfs_verify_change_attribute(dir, dentry->d_time))
+ return 0;
+ /* Revalidate nfsi->cache_change_attribute before we declare a match */
+ if (nfs_mapping_need_revalidate_inode(dir)) {
+ if (rcu_walk)
+ return 0;
+ if (__nfs_revalidate_inode(NFS_SERVER(dir), dir) < 0)
+ return 0;
+ }
+ if (!nfs_verify_change_attribute(dir, dentry->d_time))
+ return 0;
+ return 1;
+}
+
+/*
+ * Use intent information to check whether or not we're going to do
+ * an O_EXCL create using this path component.
+ */
+static int nfs_is_exclusive_create(struct inode *dir, unsigned int flags)
+{
+ if (NFS_PROTO(dir)->version == 2)
+ return 0;
+ return flags & LOOKUP_EXCL;
+}
+
+/*
+ * Inode and filehandle revalidation for lookups.
+ *
+ * We force revalidation in the cases where the VFS sets LOOKUP_REVAL,
+ * or if the intent information indicates that we're about to open this
+ * particular file and the "nocto" mount flag is not set.
+ *
+ */
+static
+int nfs_lookup_verify_inode(struct inode *inode, unsigned int flags)
+{
+ struct nfs_server *server = NFS_SERVER(inode);
+ int ret;
+
+ if (IS_AUTOMOUNT(inode))
+ return 0;
+ /* VFS wants an on-the-wire revalidation */
+ if (flags & LOOKUP_REVAL)
+ goto out_force;
+ /* This is an open(2) */
+ if ((flags & LOOKUP_OPEN) && !(server->flags & NFS_MOUNT_NOCTO) &&
+ (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)))
+ goto out_force;
+out:
+ return (inode->i_nlink == 0) ? -ENOENT : 0;
+out_force:
+ if (flags & LOOKUP_RCU)
+ return -ECHILD;
+ ret = __nfs_revalidate_inode(server, inode);
+ if (ret != 0)
+ return ret;
+ goto out;
+}
+
+/*
+ * We judge how long we want to trust negative
+ * dentries by looking at the parent inode mtime.
+ *
+ * If parent mtime has changed, we revalidate, else we wait for a
+ * period corresponding to the parent's attribute cache timeout value.
+ *
+ * If LOOKUP_RCU prevents us from performing a full check, return 1
+ * suggesting a reval is needed.
+ */
+static inline
+int nfs_neg_need_reval(struct inode *dir, struct dentry *dentry,
+ unsigned int flags)
+{
+ /* Don't revalidate a negative dentry if we're creating a new file */
+ if (flags & LOOKUP_CREATE)
+ return 0;
+ if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG)
+ return 1;
+ return !nfs_check_verifier(dir, dentry, flags & LOOKUP_RCU);
+}
+
+static int
+nfs_lookup_revalidate_done(struct inode *dir, struct dentry *dentry,
+ struct inode *inode, int error)
+{
+ switch (error) {
+ case 1:
+ dfprintk(LOOKUPCACHE, "NFS: %s(%pd2) is valid\n",
+ __func__, dentry);
+ return 1;
+ case 0:
+ nfs_mark_for_revalidate(dir);
+ if (inode && S_ISDIR(inode->i_mode)) {
+ /* Purge readdir caches. */
+ nfs_zap_caches(inode);
+ /*
+ * We can't d_drop the root of a disconnected tree:
+ * its d_hash is on the s_anon list and d_drop() would hide
+ * it from shrink_dcache_for_unmount(), leading to busy
+ * inodes on unmount and further oopses.
+ */
+ if (IS_ROOT(dentry))
+ return 1;
+ }
+ dfprintk(LOOKUPCACHE, "NFS: %s(%pd2) is invalid\n",
+ __func__, dentry);
+ return 0;
+ }
+ dfprintk(LOOKUPCACHE, "NFS: %s(%pd2) lookup returned error %d\n",
+ __func__, dentry, error);
+ return error;
+}
+
+static int
+nfs_lookup_revalidate_negative(struct inode *dir, struct dentry *dentry,
+ unsigned int flags)
+{
+ int ret = 1;
+ if (nfs_neg_need_reval(dir, dentry, flags)) {
+ if (flags & LOOKUP_RCU)
+ return -ECHILD;
+ ret = 0;
+ }
+ return nfs_lookup_revalidate_done(dir, dentry, NULL, ret);
+}
+
+static int
+nfs_lookup_revalidate_delegated(struct inode *dir, struct dentry *dentry,
+ struct inode *inode)
+{
+ nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
+ return nfs_lookup_revalidate_done(dir, dentry, inode, 1);
+}
+
+static int
+nfs_lookup_revalidate_dentry(struct inode *dir, struct dentry *dentry,
+ struct inode *inode)
+{
+ struct nfs_fh *fhandle;
+ struct nfs_fattr *fattr;
+ struct nfs4_label *label;
+ int ret;
+
+ ret = -ENOMEM;
+ fhandle = nfs_alloc_fhandle();
+ fattr = nfs_alloc_fattr();
+ label = nfs4_label_alloc(NFS_SERVER(inode), GFP_KERNEL);
+ if (fhandle == NULL || fattr == NULL || IS_ERR(label))
+ goto out;
+
+ ret = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr, label);
+ if (ret < 0) {
+ if (ret == -ESTALE || ret == -ENOENT)
+ ret = 0;
+ goto out;
+ }
+ ret = 0;
+ if (nfs_compare_fh(NFS_FH(inode), fhandle))
+ goto out;
+ if (nfs_refresh_inode(inode, fattr) < 0)
+ goto out;
+
+ nfs_setsecurity(inode, fattr, label);
+ nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
+
+ /* set a readdirplus hint that we had a cache miss */
+ nfs_force_use_readdirplus(dir);
+ ret = 1;
+out:
+ nfs_free_fattr(fattr);
+ nfs_free_fhandle(fhandle);
+ nfs4_label_free(label);
+ return nfs_lookup_revalidate_done(dir, dentry, inode, ret);
+}
+
+/*
+ * This is called every time the dcache has a lookup hit,
+ * and we should check whether we can really trust that
+ * lookup.
+ *
+ * NOTE! The hit can be a negative hit too, don't assume
+ * we have an inode!
+ *
+ * If the parent directory is seen to have changed, we throw out the
+ * cached dentry and do a new lookup.
+ */
+static int
+nfs_do_lookup_revalidate(struct inode *dir, struct dentry *dentry,
+ unsigned int flags)
+{
+ struct inode *inode;
+ int error;
+
+ nfs_inc_stats(dir, NFSIOS_DENTRYREVALIDATE);
+ inode = d_inode(dentry);
+
+ if (!inode)
+ return nfs_lookup_revalidate_negative(dir, dentry, flags);
+
+ if (is_bad_inode(inode)) {
+ dfprintk(LOOKUPCACHE, "%s: %pd2 has dud inode\n",
+ __func__, dentry);
+ goto out_bad;
+ }
+
+ if (NFS_PROTO(dir)->have_delegation(inode, FMODE_READ))
+ return nfs_lookup_revalidate_delegated(dir, dentry, inode);
+
+ /* Force a full look up iff the parent directory has changed */
+ if (!nfs_is_exclusive_create(dir, flags) &&
+ nfs_check_verifier(dir, dentry, flags & LOOKUP_RCU)) {
+ error = nfs_lookup_verify_inode(inode, flags);
+ if (error) {
+ if (error == -ESTALE)
+ nfs_zap_caches(dir);
+ goto out_bad;
+ }
+ nfs_advise_use_readdirplus(dir);
+ goto out_valid;
+ }
+
+ if (flags & LOOKUP_RCU)
+ return -ECHILD;
+
+ if (NFS_STALE(inode))
+ goto out_bad;
+
+ trace_nfs_lookup_revalidate_enter(dir, dentry, flags);
+ error = nfs_lookup_revalidate_dentry(dir, dentry, inode);
+ trace_nfs_lookup_revalidate_exit(dir, dentry, flags, error);
+ return error;
+out_valid:
+ return nfs_lookup_revalidate_done(dir, dentry, inode, 1);
+out_bad:
+ if (flags & LOOKUP_RCU)
+ return -ECHILD;
+ return nfs_lookup_revalidate_done(dir, dentry, inode, 0);
+}
+
+static int
+__nfs_lookup_revalidate(struct dentry *dentry, unsigned int flags,
+ int (*reval)(struct inode *, struct dentry *, unsigned int))
+{
+ struct dentry *parent;
+ struct inode *dir;
+ int ret;
+
+ if (flags & LOOKUP_RCU) {
+ parent = ACCESS_ONCE(dentry->d_parent);
+ dir = d_inode_rcu(parent);
+ if (!dir)
+ return -ECHILD;
+ ret = reval(dir, dentry, flags);
+ if (parent != ACCESS_ONCE(dentry->d_parent))
+ return -ECHILD;
+ } else {
+ parent = dget_parent(dentry);
+ ret = reval(d_inode(parent), dentry, flags);
+ dput(parent);
+ }
+ return ret;
+}
+
+static int nfs_lookup_revalidate(struct dentry *dentry, unsigned int flags)
+{
+ return __nfs_lookup_revalidate(dentry, flags, nfs_do_lookup_revalidate);
+}
+
+/*
+ * A weaker form of d_revalidate for revalidating just the d_inode(dentry)
+ * when we don't really care about the dentry name. This is called when a
+ * pathwalk ends on a dentry that was not found via a normal lookup in the
+ * parent dir (e.g.: ".", "..", procfs symlinks or mountpoint traversals).
+ *
+ * In this situation, we just want to verify that the inode itself is OK
+ * since the dentry might have changed on the server.
+ */
+static int nfs_weak_revalidate(struct dentry *dentry, unsigned int flags)
+{
+ struct inode *inode = d_inode(dentry);
+ int error = 0;
+
+ /*
+ * I believe we can only get a negative dentry here in the case of a
+ * procfs-style symlink. Just assume it's correct for now, but we may
+ * eventually need to do something more here.
+ */
+ if (!inode) {
+ dfprintk(LOOKUPCACHE, "%s: %pd2 has negative inode\n",
+ __func__, dentry);
+ return 1;
+ }
+
+ if (is_bad_inode(inode)) {
+ dfprintk(LOOKUPCACHE, "%s: %pd2 has dud inode\n",
+ __func__, dentry);
+ return 0;
+ }
+
+ error = nfs_lookup_verify_inode(inode, flags);
+ dfprintk(LOOKUPCACHE, "NFS: %s: inode %lu is %s\n",
+ __func__, inode->i_ino, error ? "invalid" : "valid");
+ return !error;
+}
+
+/*
+ * This is called from dput() when d_count is going to 0.
+ */
+static int nfs_dentry_delete(const struct dentry *dentry)
+{
+ dfprintk(VFS, "NFS: dentry_delete(%pd2, %x)\n",
+ dentry, dentry->d_flags);
+
+ /* Unhash any dentry with a stale inode */
+ if (d_really_is_positive(dentry) && NFS_STALE(d_inode(dentry)))
+ return 1;
+
+ if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
+ /* Unhash it, so that ->d_iput() would be called */
+ return 1;
+ }
+ if (!(dentry->d_sb->s_flags & MS_ACTIVE)) {
+ /* Unhash it, so that ancestors of killed async unlink
+ * files will be cleaned up during umount */
+ return 1;
+ }
+ return 0;
+
+}
+
+/* Ensure that we revalidate inode->i_nlink */
+static void nfs_drop_nlink(struct inode *inode)
+{
+ spin_lock(&inode->i_lock);
+ /* drop the inode if we're reasonably sure this is the last link */
+ if (inode->i_nlink == 1)
+ clear_nlink(inode);
+ NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ATTR;
+ spin_unlock(&inode->i_lock);
+}
+
+/*
+ * Called when the dentry loses inode.
+ * We use it to clean up silly-renamed files.
+ */
+static void nfs_dentry_iput(struct dentry *dentry, struct inode *inode)
+{
+ if (S_ISDIR(inode->i_mode))
+ /* drop any readdir cache as it could easily be old */
+ NFS_I(inode)->cache_validity |= NFS_INO_INVALID_DATA;
+
+ if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
+ nfs_complete_unlink(dentry, inode);
+ nfs_drop_nlink(inode);
+ }
+ iput(inode);
+}
+
+static void nfs_d_release(struct dentry *dentry)
+{
+ /* free cached devname value, if it survived that far */
+ if (unlikely(dentry->d_fsdata)) {
+ if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
+ WARN_ON(1);
+ else
+ kfree(dentry->d_fsdata);
+ }
+}
+
+const struct dentry_operations nfs_dentry_operations = {
+ .d_revalidate = nfs_lookup_revalidate,
+ .d_weak_revalidate = nfs_weak_revalidate,
+ .d_delete = nfs_dentry_delete,
+ .d_iput = nfs_dentry_iput,
+ .d_automount = nfs_d_automount,
+ .d_release = nfs_d_release,
+};
+EXPORT_SYMBOL_GPL(nfs_dentry_operations);
+
+struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
+{
+ struct dentry *res;
+ struct inode *inode = NULL;
+ struct nfs_fh *fhandle = NULL;
+ struct nfs_fattr *fattr = NULL;
+ struct nfs4_label *label = NULL;
+ int error;
+
+ dfprintk(VFS, "NFS: lookup(%pd2)\n", dentry);
+ nfs_inc_stats(dir, NFSIOS_VFSLOOKUP);
+
+ if (unlikely(dentry->d_name.len > NFS_SERVER(dir)->namelen))
+ return ERR_PTR(-ENAMETOOLONG);
+
+ /*
+ * If we're doing an exclusive create, optimize away the lookup
+ * but don't hash the dentry.
+ */
+ if (nfs_is_exclusive_create(dir, flags))
+ return NULL;
+
+ res = ERR_PTR(-ENOMEM);
+ fhandle = nfs_alloc_fhandle();
+ fattr = nfs_alloc_fattr();
+ if (fhandle == NULL || fattr == NULL)
+ goto out;
+
+ label = nfs4_label_alloc(NFS_SERVER(dir), GFP_NOWAIT);
+ if (IS_ERR(label))
+ goto out;
+
+ trace_nfs_lookup_enter(dir, dentry, flags);
+ error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr, label);
+ if (error == -ENOENT)
+ goto no_entry;
+ if (error < 0) {
+ res = ERR_PTR(error);
+ goto out_label;
+ }
+ inode = nfs_fhget(dentry->d_sb, fhandle, fattr, label);
+ res = ERR_CAST(inode);
+ if (IS_ERR(res))
+ goto out_label;
+
+ /* Notify readdir to use READDIRPLUS */
+ nfs_force_use_readdirplus(dir);
+
+no_entry:
+ res = d_splice_alias(inode, dentry);
+ if (res != NULL) {
+ if (IS_ERR(res))
+ goto out_label;
+ dentry = res;
+ }
+ nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
+out_label:
+ trace_nfs_lookup_exit(dir, dentry, flags, error);
+ nfs4_label_free(label);
+out:
+ nfs_free_fattr(fattr);
+ nfs_free_fhandle(fhandle);
+ return res;
+}
+EXPORT_SYMBOL_GPL(nfs_lookup);
+
+#if IS_ENABLED(CONFIG_NFS_V4)
+static int nfs4_lookup_revalidate(struct dentry *, unsigned int);
+
+const struct dentry_operations nfs4_dentry_operations = {
+ .d_revalidate = nfs4_lookup_revalidate,
+ .d_weak_revalidate = nfs_weak_revalidate,
+ .d_delete = nfs_dentry_delete,
+ .d_iput = nfs_dentry_iput,
+ .d_automount = nfs_d_automount,
+ .d_release = nfs_d_release,
+};
+EXPORT_SYMBOL_GPL(nfs4_dentry_operations);
+
+static fmode_t flags_to_mode(int flags)
+{
+ fmode_t res = (__force fmode_t)flags & FMODE_EXEC;
+ if ((flags & O_ACCMODE) != O_WRONLY)
+ res |= FMODE_READ;
+ if ((flags & O_ACCMODE) != O_RDONLY)
+ res |= FMODE_WRITE;
+ return res;
+}
+
+static struct nfs_open_context *create_nfs_open_context(struct dentry *dentry, int open_flags, struct file *filp)
+{
+ return alloc_nfs_open_context(dentry, flags_to_mode(open_flags), filp);
+}
+
+static int do_open(struct inode *inode, struct file *filp)
+{
+ nfs_fscache_open_file(inode, filp);
+ return 0;
+}
+
+static int nfs_finish_open(struct nfs_open_context *ctx,
+ struct dentry *dentry,
+ struct file *file, unsigned open_flags,
+ int *opened)
+{
+ int err;
+
+ err = finish_open(file, dentry, do_open, opened);
+ if (err)
+ goto out;
+ if (S_ISREG(file->f_path.dentry->d_inode->i_mode))
+ nfs_file_set_open_context(file, ctx);
+ else
+ err = -EOPENSTALE;
+out:
+ return err;
+}
+
+int nfs_atomic_open(struct inode *dir, struct dentry *dentry,
+ struct file *file, unsigned open_flags,
+ umode_t mode, int *opened)
+{
+ DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
+ struct nfs_open_context *ctx;
+ struct dentry *res;
+ struct iattr attr = { .ia_valid = ATTR_OPEN };
+ struct inode *inode;
+ unsigned int lookup_flags = 0;
+ bool switched = false;
+ int err;
+
+ /* Expect a negative dentry */
+ BUG_ON(d_inode(dentry));
+
+ dfprintk(VFS, "NFS: atomic_open(%s/%lu), %pd\n",
+ dir->i_sb->s_id, dir->i_ino, dentry);
+
+ err = nfs_check_flags(open_flags);
+ if (err)
+ return err;
+
+ /* NFS only supports OPEN on regular files */
+ if ((open_flags & O_DIRECTORY)) {
+ if (!d_in_lookup(dentry)) {
+ /*
+ * Hashed negative dentry with O_DIRECTORY: dentry was
+ * revalidated and is fine, no need to perform lookup
+ * again
+ */
+ return -ENOENT;
+ }
+ lookup_flags = LOOKUP_OPEN|LOOKUP_DIRECTORY;
+ goto no_open;
+ }
+
+ if (dentry->d_name.len > NFS_SERVER(dir)->namelen)
+ return -ENAMETOOLONG;
+
+ if (open_flags & O_CREAT) {
+ struct nfs_server *server = NFS_SERVER(dir);
+
+ if (!(server->attr_bitmask[2] & FATTR4_WORD2_MODE_UMASK))
+ mode &= ~current_umask();
+
+ attr.ia_valid |= ATTR_MODE;
+ attr.ia_mode = mode;
+ }
+ if (open_flags & O_TRUNC) {
+ attr.ia_valid |= ATTR_SIZE;
+ attr.ia_size = 0;
+ }
+
+ if (!(open_flags & O_CREAT) && !d_in_lookup(dentry)) {
+ d_drop(dentry);
+ switched = true;
+ dentry = d_alloc_parallel(dentry->d_parent,
+ &dentry->d_name, &wq);
+ if (IS_ERR(dentry))
+ return PTR_ERR(dentry);
+ if (unlikely(!d_in_lookup(dentry)))
+ return finish_no_open(file, dentry);
+ }
+
+ ctx = create_nfs_open_context(dentry, open_flags, file);
+ err = PTR_ERR(ctx);
+ if (IS_ERR(ctx))
+ goto out;
+
+ trace_nfs_atomic_open_enter(dir, ctx, open_flags);
+ inode = NFS_PROTO(dir)->open_context(dir, ctx, open_flags, &attr, opened);
+ if (IS_ERR(inode)) {
+ err = PTR_ERR(inode);
+ trace_nfs_atomic_open_exit(dir, ctx, open_flags, err);
+ put_nfs_open_context(ctx);
+ d_drop(dentry);
+ switch (err) {
+ case -ENOENT:
+ d_splice_alias(NULL, dentry);
+ nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
+ break;
+ case -EISDIR:
+ case -ENOTDIR:
+ goto no_open;
+ case -ELOOP:
+ if (!(open_flags & O_NOFOLLOW))
+ goto no_open;
+ break;
+ /* case -EINVAL: */
+ default:
+ break;
+ }
+ goto out;
+ }
+
+ err = nfs_finish_open(ctx, ctx->dentry, file, open_flags, opened);
+ trace_nfs_atomic_open_exit(dir, ctx, open_flags, err);
+ put_nfs_open_context(ctx);
+out:
+ if (unlikely(switched)) {
+ d_lookup_done(dentry);
+ dput(dentry);
+ }
+ return err;
+
+no_open:
+ res = nfs_lookup(dir, dentry, lookup_flags);
+ if (switched) {
+ d_lookup_done(dentry);
+ if (!res)
+ res = dentry;
+ else
+ dput(dentry);
+ }
+ if (IS_ERR(res))
+ return PTR_ERR(res);
+ return finish_no_open(file, res);
+}
+EXPORT_SYMBOL_GPL(nfs_atomic_open);
+
+static int
+nfs4_do_lookup_revalidate(struct inode *dir, struct dentry *dentry,
+ unsigned int flags)
+{
+ struct inode *inode;
+
+ if (!(flags & LOOKUP_OPEN) || (flags & LOOKUP_DIRECTORY))
+ goto full_reval;
+ if (d_mountpoint(dentry))
+ goto full_reval;
+
+ inode = d_inode(dentry);
+
+ /* We can't create new files in nfs_open_revalidate(), so we
+ * optimize away revalidation of negative dentries.
+ */
+ if (inode == NULL)
+ goto full_reval;
+
+ if (NFS_PROTO(dir)->have_delegation(inode, FMODE_READ))
+ return nfs_lookup_revalidate_delegated(dir, dentry, inode);
+
+ /* NFS only supports OPEN on regular files */
+ if (!S_ISREG(inode->i_mode))
+ goto full_reval;
+
+ /* We cannot do exclusive creation on a positive dentry */
+ if (flags & (LOOKUP_EXCL | LOOKUP_REVAL))
+ goto reval_dentry;
+
+ /* Check if the directory changed */
+ if (!nfs_check_verifier(dir, dentry, flags & LOOKUP_RCU))
+ goto reval_dentry;
+
+ /* Let f_op->open() actually open (and revalidate) the file */
+ return 1;
+reval_dentry:
+ if (flags & LOOKUP_RCU)
+ return -ECHILD;
+ return nfs_lookup_revalidate_dentry(dir, dentry, inode);;
+
+full_reval:
+ return nfs_do_lookup_revalidate(dir, dentry, flags);
+}
+
+static int nfs4_lookup_revalidate(struct dentry *dentry, unsigned int flags)
+{
+ return __nfs_lookup_revalidate(dentry, flags,
+ nfs4_do_lookup_revalidate);
+}
+
+#endif /* CONFIG_NFSV4 */
+
+/*
+ * Code common to create, mkdir, and mknod.
+ */
+int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fhandle,
+ struct nfs_fattr *fattr,
+ struct nfs4_label *label)
+{
+ struct dentry *parent = dget_parent(dentry);
+ struct inode *dir = d_inode(parent);
+ struct inode *inode;
+ int error = -EACCES;
+
+ d_drop(dentry);
+
+ /* We may have been initialized further down */
+ if (d_really_is_positive(dentry))
+ goto out;
+ if (fhandle->size == 0) {
+ error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr, NULL);
+ if (error)
+ goto out_error;
+ }
+ nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
+ if (!(fattr->valid & NFS_ATTR_FATTR)) {
+ struct nfs_server *server = NFS_SB(dentry->d_sb);
+ error = server->nfs_client->rpc_ops->getattr(server, fhandle, fattr, NULL);
+ if (error < 0)
+ goto out_error;
+ }
+ inode = nfs_fhget(dentry->d_sb, fhandle, fattr, label);
+ error = PTR_ERR(inode);
+ if (IS_ERR(inode))
+ goto out_error;
+ d_add(dentry, inode);
+out:
+ dput(parent);
+ return 0;
+out_error:
+ nfs_mark_for_revalidate(dir);
+ dput(parent);
+ return error;
+}
+EXPORT_SYMBOL_GPL(nfs_instantiate);
+
+/*
+ * Following a failed create operation, we drop the dentry rather
+ * than retain a negative dentry. This avoids a problem in the event
+ * that the operation succeeded on the server, but an error in the
+ * reply path made it appear to have failed.
+ */
+int nfs_create(struct inode *dir, struct dentry *dentry,
+ umode_t mode, bool excl)
+{
+ struct iattr attr;
+ int open_flags = excl ? O_CREAT | O_EXCL : O_CREAT;
+ int error;
+
+ dfprintk(VFS, "NFS: create(%s/%lu), %pd\n",
+ dir->i_sb->s_id, dir->i_ino, dentry);
+
+ attr.ia_mode = mode;
+ attr.ia_valid = ATTR_MODE;
+
+ trace_nfs_create_enter(dir, dentry, open_flags);
+ error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags);
+ trace_nfs_create_exit(dir, dentry, open_flags, error);
+ if (error != 0)
+ goto out_err;
+ return 0;
+out_err:
+ d_drop(dentry);
+ return error;
+}
+EXPORT_SYMBOL_GPL(nfs_create);
+
+/*
+ * See comments for nfs_proc_create regarding failed operations.
+ */
+int
+nfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev)
+{
+ struct iattr attr;
+ int status;
+
+ dfprintk(VFS, "NFS: mknod(%s/%lu), %pd\n",
+ dir->i_sb->s_id, dir->i_ino, dentry);
+
+ attr.ia_mode = mode;
+ attr.ia_valid = ATTR_MODE;
+
+ trace_nfs_mknod_enter(dir, dentry);
+ status = NFS_PROTO(dir)->mknod(dir, dentry, &attr, rdev);
+ trace_nfs_mknod_exit(dir, dentry, status);
+ if (status != 0)
+ goto out_err;
+ return 0;
+out_err:
+ d_drop(dentry);
+ return status;
+}
+EXPORT_SYMBOL_GPL(nfs_mknod);
+
+/*
+ * See comments for nfs_proc_create regarding failed operations.
+ */
+int nfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
+{
+ struct iattr attr;
+ int error;
+
+ dfprintk(VFS, "NFS: mkdir(%s/%lu), %pd\n",
+ dir->i_sb->s_id, dir->i_ino, dentry);
+
+ attr.ia_valid = ATTR_MODE;
+ attr.ia_mode = mode | S_IFDIR;
+
+ trace_nfs_mkdir_enter(dir, dentry);
+ error = NFS_PROTO(dir)->mkdir(dir, dentry, &attr);
+ trace_nfs_mkdir_exit(dir, dentry, error);
+ if (error != 0)
+ goto out_err;
+ return 0;
+out_err:
+ d_drop(dentry);
+ return error;
+}
+EXPORT_SYMBOL_GPL(nfs_mkdir);
+
+static void nfs_dentry_handle_enoent(struct dentry *dentry)
+{
+ if (simple_positive(dentry))
+ d_delete(dentry);
+}
+
+int nfs_rmdir(struct inode *dir, struct dentry *dentry)
+{
+ int error;
+
+ dfprintk(VFS, "NFS: rmdir(%s/%lu), %pd\n",
+ dir->i_sb->s_id, dir->i_ino, dentry);
+
+ trace_nfs_rmdir_enter(dir, dentry);
+ if (d_really_is_positive(dentry)) {
+ down_write(&NFS_I(d_inode(dentry))->rmdir_sem);
+ error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name);
+ /* Ensure the VFS deletes this inode */
+ switch (error) {
+ case 0:
+ clear_nlink(d_inode(dentry));
+ break;
+ case -ENOENT:
+ nfs_dentry_handle_enoent(dentry);
+ }
+ up_write(&NFS_I(d_inode(dentry))->rmdir_sem);
+ } else
+ error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name);
+ trace_nfs_rmdir_exit(dir, dentry, error);
+
+ return error;
+}
+EXPORT_SYMBOL_GPL(nfs_rmdir);
+
+/*
+ * Remove a file after making sure there are no pending writes,
+ * and after checking that the file has only one user.
+ *
+ * We invalidate the attribute cache and free the inode prior to the operation
+ * to avoid possible races if the server reuses the inode.
+ */
+static int nfs_safe_remove(struct dentry *dentry)
+{
+ struct inode *dir = d_inode(dentry->d_parent);
+ struct inode *inode = d_inode(dentry);
+ int error = -EBUSY;
+
+ dfprintk(VFS, "NFS: safe_remove(%pd2)\n", dentry);
+
+ /* If the dentry was sillyrenamed, we simply call d_delete() */
+ if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
+ error = 0;
+ goto out;
+ }
+
+ trace_nfs_remove_enter(dir, dentry);
+ if (inode != NULL) {
+ NFS_PROTO(inode)->return_delegation(inode);
+ error = NFS_PROTO(dir)->remove(dir, &dentry->d_name);
+ if (error == 0)
+ nfs_drop_nlink(inode);
+ } else
+ error = NFS_PROTO(dir)->remove(dir, &dentry->d_name);
+ if (error == -ENOENT)
+ nfs_dentry_handle_enoent(dentry);
+ trace_nfs_remove_exit(dir, dentry, error);
+out:
+ return error;
+}
+
+/* We do silly rename. In case sillyrename() returns -EBUSY, the inode
+ * belongs to an active ".nfs..." file and we return -EBUSY.
+ *
+ * If sillyrename() returns 0, we do nothing, otherwise we unlink.
+ */
+int nfs_unlink(struct inode *dir, struct dentry *dentry)
+{
+ int error;
+ int need_rehash = 0;
+
+ dfprintk(VFS, "NFS: unlink(%s/%lu, %pd)\n", dir->i_sb->s_id,
+ dir->i_ino, dentry);
+
+ trace_nfs_unlink_enter(dir, dentry);
+ spin_lock(&dentry->d_lock);
+ if (d_count(dentry) > 1) {
+ spin_unlock(&dentry->d_lock);
+ /* Start asynchronous writeout of the inode */
+ write_inode_now(d_inode(dentry), 0);
+ error = nfs_sillyrename(dir, dentry);
+ goto out;
+ }
+ if (!d_unhashed(dentry)) {
+ __d_drop(dentry);
+ need_rehash = 1;
+ }
+ spin_unlock(&dentry->d_lock);
+ error = nfs_safe_remove(dentry);
+ if (!error || error == -ENOENT) {
+ nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
+ } else if (need_rehash)
+ d_rehash(dentry);
+out:
+ trace_nfs_unlink_exit(dir, dentry, error);
+ return error;
+}
+EXPORT_SYMBOL_GPL(nfs_unlink);
+
+/*
+ * To create a symbolic link, most file systems instantiate a new inode,
+ * add a page to it containing the path, then write it out to the disk
+ * using prepare_write/commit_write.
+ *
+ * Unfortunately the NFS client can't create the in-core inode first
+ * because it needs a file handle to create an in-core inode (see
+ * fs/nfs/inode.c:nfs_fhget). We only have a file handle *after* the
+ * symlink request has completed on the server.
+ *
+ * So instead we allocate a raw page, copy the symname into it, then do
+ * the SYMLINK request with the page as the buffer. If it succeeds, we
+ * now have a new file handle and can instantiate an in-core NFS inode
+ * and move the raw page into its mapping.
+ */
+int nfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
+{
+ struct page *page;
+ char *kaddr;
+ struct iattr attr;
+ unsigned int pathlen = strlen(symname);
+ int error;
+
+ dfprintk(VFS, "NFS: symlink(%s/%lu, %pd, %s)\n", dir->i_sb->s_id,
+ dir->i_ino, dentry, symname);
+
+ if (pathlen > PAGE_SIZE)
+ return -ENAMETOOLONG;
+
+ attr.ia_mode = S_IFLNK | S_IRWXUGO;
+ attr.ia_valid = ATTR_MODE;
+
+ page = alloc_page(GFP_USER);
+ if (!page)
+ return -ENOMEM;
+
+ kaddr = page_address(page);
+ memcpy(kaddr, symname, pathlen);
+ if (pathlen < PAGE_SIZE)
+ memset(kaddr + pathlen, 0, PAGE_SIZE - pathlen);
+
+ trace_nfs_symlink_enter(dir, dentry);
+ error = NFS_PROTO(dir)->symlink(dir, dentry, page, pathlen, &attr);
+ trace_nfs_symlink_exit(dir, dentry, error);
+ if (error != 0) {
+ dfprintk(VFS, "NFS: symlink(%s/%lu, %pd, %s) error %d\n",
+ dir->i_sb->s_id, dir->i_ino,
+ dentry, symname, error);
+ d_drop(dentry);
+ __free_page(page);
+ return error;
+ }
+
+ /*
+ * No big deal if we can't add this page to the page cache here.
+ * READLINK will get the missing page from the server if needed.
+ */
+ if (!add_to_page_cache_lru(page, d_inode(dentry)->i_mapping, 0,
+ GFP_KERNEL)) {
+ SetPageUptodate(page);
+ unlock_page(page);
+ /*
+ * add_to_page_cache_lru() grabs an extra page refcount.
+ * Drop it here to avoid leaking this page later.
+ */
+ put_page(page);
+ } else
+ __free_page(page);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(nfs_symlink);
+
+int
+nfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
+{
+ struct inode *inode = d_inode(old_dentry);
+ int error;
+
+ dfprintk(VFS, "NFS: link(%pd2 -> %pd2)\n",
+ old_dentry, dentry);
+
+ trace_nfs_link_enter(inode, dir, dentry);
+ NFS_PROTO(inode)->return_delegation(inode);
+
+ d_drop(dentry);
+ error = NFS_PROTO(dir)->link(inode, dir, &dentry->d_name);
+ if (error == 0) {
+ ihold(inode);
+ d_add(dentry, inode);
+ }
+ trace_nfs_link_exit(inode, dir, dentry, error);
+ return error;
+}
+EXPORT_SYMBOL_GPL(nfs_link);
+
+/*
+ * RENAME
+ * FIXME: Some nfsds, like the Linux user space nfsd, may generate a
+ * different file handle for the same inode after a rename (e.g. when
+ * moving to a different directory). A fail-safe method to do so would
+ * be to look up old_dir/old_name, create a link to new_dir/new_name and
+ * rename the old file using the sillyrename stuff. This way, the original
+ * file in old_dir will go away when the last process iput()s the inode.
+ *
+ * FIXED.
+ *
+ * It actually works quite well. One needs to have the possibility for
+ * at least one ".nfs..." file in each directory the file ever gets
+ * moved or linked to which happens automagically with the new
+ * implementation that only depends on the dcache stuff instead of
+ * using the inode layer
+ *
+ * Unfortunately, things are a little more complicated than indicated
+ * above. For a cross-directory move, we want to make sure we can get
+ * rid of the old inode after the operation. This means there must be
+ * no pending writes (if it's a file), and the use count must be 1.
+ * If these conditions are met, we can drop the dentries before doing
+ * the rename.
+ */
+int nfs_rename(struct inode *old_dir, struct dentry *old_dentry,
+ struct inode *new_dir, struct dentry *new_dentry,
+ unsigned int flags)
+{
+ struct inode *old_inode = d_inode(old_dentry);
+ struct inode *new_inode = d_inode(new_dentry);
+ struct dentry *dentry = NULL, *rehash = NULL;
+ struct rpc_task *task;
+ int error = -EBUSY;
+
+ if (flags)
+ return -EINVAL;
+
+ dfprintk(VFS, "NFS: rename(%pd2 -> %pd2, ct=%d)\n",
+ old_dentry, new_dentry,
+ d_count(new_dentry));
+
+ trace_nfs_rename_enter(old_dir, old_dentry, new_dir, new_dentry);
+ /*
+ * For non-directories, check whether the target is busy and if so,
+ * make a copy of the dentry and then do a silly-rename. If the
+ * silly-rename succeeds, the copied dentry is hashed and becomes
+ * the new target.
+ */
+ if (new_inode && !S_ISDIR(new_inode->i_mode)) {
+ /*
+ * To prevent any new references to the target during the
+ * rename, we unhash the dentry in advance.
+ */
+ if (!d_unhashed(new_dentry)) {
+ d_drop(new_dentry);
+ rehash = new_dentry;
+ }
+
+ if (d_count(new_dentry) > 2) {
+ int err;
+
+ /* copy the target dentry's name */
+ dentry = d_alloc(new_dentry->d_parent,
+ &new_dentry->d_name);
+ if (!dentry)
+ goto out;
+
+ /* silly-rename the existing target ... */
+ err = nfs_sillyrename(new_dir, new_dentry);
+ if (err)
+ goto out;
+
+ new_dentry = dentry;
+ rehash = NULL;
+ new_inode = NULL;
+ }
+ }
+
+ NFS_PROTO(old_inode)->return_delegation(old_inode);
+ if (new_inode != NULL)
+ NFS_PROTO(new_inode)->return_delegation(new_inode);
+
+ task = nfs_async_rename(old_dir, new_dir, old_dentry, new_dentry, NULL);
+ if (IS_ERR(task)) {
+ error = PTR_ERR(task);
+ goto out;
+ }
+
+ error = rpc_wait_for_completion_task(task);
+ if (error != 0) {
+ ((struct nfs_renamedata *)task->tk_calldata)->cancelled = 1;
+ /* Paired with the atomic_dec_and_test() barrier in rpc_do_put_task() */
+ smp_wmb();
+ } else
+ error = task->tk_status;
+ rpc_put_task(task);
+ nfs_mark_for_revalidate(old_inode);
+out:
+ if (rehash)
+ d_rehash(rehash);
+ trace_nfs_rename_exit(old_dir, old_dentry,
+ new_dir, new_dentry, error);
+ if (!error) {
+ if (new_inode != NULL)
+ nfs_drop_nlink(new_inode);
+ /*
+ * The d_move() should be here instead of in an async RPC completion
+ * handler because we need the proper locks to move the dentry. If
+ * we're interrupted by a signal, the async RPC completion handler
+ * should mark the directories for revalidation.
+ */
+ d_move(old_dentry, new_dentry);
+ nfs_set_verifier(old_dentry,
+ nfs_save_change_attribute(new_dir));
+ } else if (error == -ENOENT)
+ nfs_dentry_handle_enoent(old_dentry);
+
+ /* new dentry created? */
+ if (dentry)
+ dput(dentry);
+ return error;
+}
+EXPORT_SYMBOL_GPL(nfs_rename);
+
+static DEFINE_SPINLOCK(nfs_access_lru_lock);
+static LIST_HEAD(nfs_access_lru_list);
+static atomic_long_t nfs_access_nr_entries;
+
+static unsigned long nfs_access_max_cachesize = ULONG_MAX;
+module_param(nfs_access_max_cachesize, ulong, 0644);
+MODULE_PARM_DESC(nfs_access_max_cachesize, "NFS access maximum total cache length");
+
+static void nfs_access_free_entry(struct nfs_access_entry *entry)
+{
+ put_rpccred(entry->cred);
+ kfree_rcu(entry, rcu_head);
+ smp_mb__before_atomic();
+ atomic_long_dec(&nfs_access_nr_entries);
+ smp_mb__after_atomic();
+}
+
+static void nfs_access_free_list(struct list_head *head)
+{
+ struct nfs_access_entry *cache;
+
+ while (!list_empty(head)) {
+ cache = list_entry(head->next, struct nfs_access_entry, lru);
+ list_del(&cache->lru);
+ nfs_access_free_entry(cache);
+ }
+}
+
+static unsigned long
+nfs_do_access_cache_scan(unsigned int nr_to_scan)
+{
+ LIST_HEAD(head);
+ struct nfs_inode *nfsi, *next;
+ struct nfs_access_entry *cache;
+ long freed = 0;
+
+ spin_lock(&nfs_access_lru_lock);
+ list_for_each_entry_safe(nfsi, next, &nfs_access_lru_list, access_cache_inode_lru) {
+ struct inode *inode;
+
+ if (nr_to_scan-- == 0)
+ break;
+ inode = &nfsi->vfs_inode;
+ spin_lock(&inode->i_lock);
+ if (list_empty(&nfsi->access_cache_entry_lru))
+ goto remove_lru_entry;
+ cache = list_entry(nfsi->access_cache_entry_lru.next,
+ struct nfs_access_entry, lru);
+ list_move(&cache->lru, &head);
+ rb_erase(&cache->rb_node, &nfsi->access_cache);
+ freed++;
+ if (!list_empty(&nfsi->access_cache_entry_lru))
+ list_move_tail(&nfsi->access_cache_inode_lru,
+ &nfs_access_lru_list);
+ else {
+remove_lru_entry:
+ list_del_init(&nfsi->access_cache_inode_lru);
+ smp_mb__before_atomic();
+ clear_bit(NFS_INO_ACL_LRU_SET, &nfsi->flags);
+ smp_mb__after_atomic();
+ }
+ spin_unlock(&inode->i_lock);
+ }
+ spin_unlock(&nfs_access_lru_lock);
+ nfs_access_free_list(&head);
+ return freed;
+}
+
+unsigned long
+nfs_access_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
+{
+ int nr_to_scan = sc->nr_to_scan;
+ gfp_t gfp_mask = sc->gfp_mask;
+
+ if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL)
+ return SHRINK_STOP;
+ return nfs_do_access_cache_scan(nr_to_scan);
+}
+
+
+unsigned long
+nfs_access_cache_count(struct shrinker *shrink, struct shrink_control *sc)
+{
+ return vfs_pressure_ratio(atomic_long_read(&nfs_access_nr_entries));
+}
+
+static void
+nfs_access_cache_enforce_limit(void)
+{
+ long nr_entries = atomic_long_read(&nfs_access_nr_entries);
+ unsigned long diff;
+ unsigned int nr_to_scan;
+
+ if (nr_entries < 0 || nr_entries <= nfs_access_max_cachesize)
+ return;
+ nr_to_scan = 100;
+ diff = nr_entries - nfs_access_max_cachesize;
+ if (diff < nr_to_scan)
+ nr_to_scan = diff;
+ nfs_do_access_cache_scan(nr_to_scan);
+}
+
+static void __nfs_access_zap_cache(struct nfs_inode *nfsi, struct list_head *head)
+{
+ struct rb_root *root_node = &nfsi->access_cache;
+ struct rb_node *n;
+ struct nfs_access_entry *entry;
+
+ /* Unhook entries from the cache */
+ while ((n = rb_first(root_node)) != NULL) {
+ entry = rb_entry(n, struct nfs_access_entry, rb_node);
+ rb_erase(n, root_node);
+ list_move(&entry->lru, head);
+ }
+ nfsi->cache_validity &= ~NFS_INO_INVALID_ACCESS;
+}
+
+void nfs_access_zap_cache(struct inode *inode)
+{
+ LIST_HEAD(head);
+
+ if (test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags) == 0)
+ return;
+ /* Remove from global LRU init */
+ spin_lock(&nfs_access_lru_lock);
+ if (test_and_clear_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags))
+ list_del_init(&NFS_I(inode)->access_cache_inode_lru);
+
+ spin_lock(&inode->i_lock);
+ __nfs_access_zap_cache(NFS_I(inode), &head);
+ spin_unlock(&inode->i_lock);
+ spin_unlock(&nfs_access_lru_lock);
+ nfs_access_free_list(&head);
+}
+EXPORT_SYMBOL_GPL(nfs_access_zap_cache);
+
+static struct nfs_access_entry *nfs_access_search_rbtree(struct inode *inode, struct rpc_cred *cred)
+{
+ struct rb_node *n = NFS_I(inode)->access_cache.rb_node;
+ struct nfs_access_entry *entry;
+
+ while (n != NULL) {
+ entry = rb_entry(n, struct nfs_access_entry, rb_node);
+
+ if (cred < entry->cred)
+ n = n->rb_left;
+ else if (cred > entry->cred)
+ n = n->rb_right;
+ else
+ return entry;
+ }
+ return NULL;
+}
+
+static int nfs_access_get_cached(struct inode *inode, struct rpc_cred *cred, struct nfs_access_entry *res, bool may_block)
+{
+ struct nfs_inode *nfsi = NFS_I(inode);
+ struct nfs_access_entry *cache;
+ bool retry = true;
+ int err;
+
+ spin_lock(&inode->i_lock);
+ for(;;) {
+ if (nfsi->cache_validity & NFS_INO_INVALID_ACCESS)
+ goto out_zap;
+ cache = nfs_access_search_rbtree(inode, cred);
+ err = -ENOENT;
+ if (cache == NULL)
+ goto out;
+ /* Found an entry, is our attribute cache valid? */
+ if (!nfs_check_cache_invalid(inode, NFS_INO_INVALID_ACCESS))
+ break;
+ err = -ECHILD;
+ if (!may_block)
+ goto out;
+ if (!retry)
+ goto out_zap;
+ spin_unlock(&inode->i_lock);
+ err = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
+ if (err)
+ return err;
+ spin_lock(&inode->i_lock);
+ retry = false;
+ }
+ res->cred = cache->cred;
+ res->mask = cache->mask;
+ list_move_tail(&cache->lru, &nfsi->access_cache_entry_lru);
+ err = 0;
+out:
+ spin_unlock(&inode->i_lock);
+ return err;
+out_zap:
+ spin_unlock(&inode->i_lock);
+ nfs_access_zap_cache(inode);
+ return -ENOENT;
+}
+
+static int nfs_access_get_cached_rcu(struct inode *inode, struct rpc_cred *cred, struct nfs_access_entry *res)
+{
+ /* Only check the most recently returned cache entry,
+ * but do it without locking.
+ */
+ struct nfs_inode *nfsi = NFS_I(inode);
+ struct nfs_access_entry *cache;
+ int err = -ECHILD;
+ struct list_head *lh;
+
+ rcu_read_lock();
+ if (nfsi->cache_validity & NFS_INO_INVALID_ACCESS)
+ goto out;
+ lh = rcu_dereference(nfsi->access_cache_entry_lru.prev);
+ cache = list_entry(lh, struct nfs_access_entry, lru);
+ if (lh == &nfsi->access_cache_entry_lru ||
+ cred != cache->cred)
+ cache = NULL;
+ if (cache == NULL)
+ goto out;
+ if (nfs_check_cache_invalid(inode, NFS_INO_INVALID_ACCESS))
+ goto out;
+ res->cred = cache->cred;
+ res->mask = cache->mask;
+ err = 0;
+out:
+ rcu_read_unlock();
+ return err;
+}
+
+static void nfs_access_add_rbtree(struct inode *inode, struct nfs_access_entry *set)
+{
+ struct nfs_inode *nfsi = NFS_I(inode);
+ struct rb_root *root_node = &nfsi->access_cache;
+ struct rb_node **p = &root_node->rb_node;
+ struct rb_node *parent = NULL;
+ struct nfs_access_entry *entry;
+
+ spin_lock(&inode->i_lock);
+ while (*p != NULL) {
+ parent = *p;
+ entry = rb_entry(parent, struct nfs_access_entry, rb_node);
+
+ if (set->cred < entry->cred)
+ p = &parent->rb_left;
+ else if (set->cred > entry->cred)
+ p = &parent->rb_right;
+ else
+ goto found;
+ }
+ rb_link_node(&set->rb_node, parent, p);
+ rb_insert_color(&set->rb_node, root_node);
+ list_add_tail(&set->lru, &nfsi->access_cache_entry_lru);
+ spin_unlock(&inode->i_lock);
+ return;
+found:
+ rb_replace_node(parent, &set->rb_node, root_node);
+ list_add_tail(&set->lru, &nfsi->access_cache_entry_lru);
+ list_del(&entry->lru);
+ spin_unlock(&inode->i_lock);
+ nfs_access_free_entry(entry);
+}
+
+void nfs_access_add_cache(struct inode *inode, struct nfs_access_entry *set)
+{
+ struct nfs_access_entry *cache = kmalloc(sizeof(*cache), GFP_KERNEL);
+ if (cache == NULL)
+ return;
+ RB_CLEAR_NODE(&cache->rb_node);
+ cache->cred = get_rpccred(set->cred);
+ cache->mask = set->mask;
+
+ /* The above field assignments must be visible
+ * before this item appears on the lru. We cannot easily
+ * use rcu_assign_pointer, so just force the memory barrier.
+ */
+ smp_wmb();
+ nfs_access_add_rbtree(inode, cache);
+
+ /* Update accounting */
+ smp_mb__before_atomic();
+ atomic_long_inc(&nfs_access_nr_entries);
+ smp_mb__after_atomic();
+
+ /* Add inode to global LRU list */
+ if (!test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) {
+ spin_lock(&nfs_access_lru_lock);
+ if (!test_and_set_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags))
+ list_add_tail(&NFS_I(inode)->access_cache_inode_lru,
+ &nfs_access_lru_list);
+ spin_unlock(&nfs_access_lru_lock);
+ }
+ nfs_access_cache_enforce_limit();
+}
+EXPORT_SYMBOL_GPL(nfs_access_add_cache);
+
+#define NFS_MAY_READ (NFS4_ACCESS_READ)
+#define NFS_MAY_WRITE (NFS4_ACCESS_MODIFY | \
+ NFS4_ACCESS_EXTEND | \
+ NFS4_ACCESS_DELETE)
+#define NFS_FILE_MAY_WRITE (NFS4_ACCESS_MODIFY | \
+ NFS4_ACCESS_EXTEND)
+#define NFS_DIR_MAY_WRITE NFS_MAY_WRITE
+#define NFS_MAY_LOOKUP (NFS4_ACCESS_LOOKUP)
+#define NFS_MAY_EXECUTE (NFS4_ACCESS_EXECUTE)
+static int
+nfs_access_calc_mask(u32 access_result, umode_t umode)
+{
+ int mask = 0;
+
+ if (access_result & NFS_MAY_READ)
+ mask |= MAY_READ;
+ if (S_ISDIR(umode)) {
+ if ((access_result & NFS_DIR_MAY_WRITE) == NFS_DIR_MAY_WRITE)
+ mask |= MAY_WRITE;
+ if ((access_result & NFS_MAY_LOOKUP) == NFS_MAY_LOOKUP)
+ mask |= MAY_EXEC;
+ } else if (S_ISREG(umode)) {
+ if ((access_result & NFS_FILE_MAY_WRITE) == NFS_FILE_MAY_WRITE)
+ mask |= MAY_WRITE;
+ if ((access_result & NFS_MAY_EXECUTE) == NFS_MAY_EXECUTE)
+ mask |= MAY_EXEC;
+ } else if (access_result & NFS_MAY_WRITE)
+ mask |= MAY_WRITE;
+ return mask;
+}
+
+void nfs_access_set_mask(struct nfs_access_entry *entry, u32 access_result)
+{
+ entry->mask = access_result;
+}
+EXPORT_SYMBOL_GPL(nfs_access_set_mask);
+
+static int nfs_do_access(struct inode *inode, struct rpc_cred *cred, int mask)
+{
+ struct nfs_access_entry cache;
+ bool may_block = (mask & MAY_NOT_BLOCK) == 0;
+ int cache_mask;
+ int status;
+
+ trace_nfs_access_enter(inode);
+
+ status = nfs_access_get_cached_rcu(inode, cred, &cache);
+ if (status != 0)
+ status = nfs_access_get_cached(inode, cred, &cache, may_block);
+ if (status == 0)
+ goto out_cached;
+
+ status = -ECHILD;
+ if (!may_block)
+ goto out;
+
+ /* Be clever: ask server to check for all possible rights */
+ cache.mask = NFS_MAY_LOOKUP | NFS_MAY_EXECUTE
+ | NFS_MAY_WRITE | NFS_MAY_READ;
+ cache.cred = cred;
+ status = NFS_PROTO(inode)->access(inode, &cache);
+ if (status != 0) {
+ if (status == -ESTALE) {
+ nfs_zap_caches(inode);
+ if (!S_ISDIR(inode->i_mode))
+ set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
+ }
+ goto out;
+ }
+ nfs_access_add_cache(inode, &cache);
+out_cached:
+ cache_mask = nfs_access_calc_mask(cache.mask, inode->i_mode);
+ if ((mask & ~cache_mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) != 0)
+ status = -EACCES;
+out:
+ trace_nfs_access_exit(inode, status);
+ return status;
+}
+
+static int nfs_open_permission_mask(int openflags)
+{
+ int mask = 0;
+
+ if (openflags & __FMODE_EXEC) {
+ /* ONLY check exec rights */
+ mask = MAY_EXEC;
+ } else {
+ if ((openflags & O_ACCMODE) != O_WRONLY)
+ mask |= MAY_READ;
+ if ((openflags & O_ACCMODE) != O_RDONLY)
+ mask |= MAY_WRITE;
+ }
+
+ return mask;
+}
+
+int nfs_may_open(struct inode *inode, struct rpc_cred *cred, int openflags)
+{
+ return nfs_do_access(inode, cred, nfs_open_permission_mask(openflags));
+}
+EXPORT_SYMBOL_GPL(nfs_may_open);
+
+static int nfs_execute_ok(struct inode *inode, int mask)
+{
+ struct nfs_server *server = NFS_SERVER(inode);
+ int ret = 0;
+
+ if (nfs_check_cache_invalid(inode, NFS_INO_INVALID_ACCESS)) {
+ if (mask & MAY_NOT_BLOCK)
+ return -ECHILD;
+ ret = __nfs_revalidate_inode(server, inode);
+ }
+ if (ret == 0 && !execute_ok(inode))
+ ret = -EACCES;
+ return ret;
+}
+
+int nfs_permission(struct inode *inode, int mask)
+{
+ struct rpc_cred *cred;
+ int res = 0;
+
+ nfs_inc_stats(inode, NFSIOS_VFSACCESS);
+
+ if ((mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0)
+ goto out;
+ /* Is this sys_access() ? */
+ if (mask & (MAY_ACCESS | MAY_CHDIR))
+ goto force_lookup;
+
+ switch (inode->i_mode & S_IFMT) {
+ case S_IFLNK:
+ goto out;
+ case S_IFREG:
+ if ((mask & MAY_OPEN) &&
+ nfs_server_capable(inode, NFS_CAP_ATOMIC_OPEN))
+ return 0;
+ break;
+ case S_IFDIR:
+ /*
+ * Optimize away all write operations, since the server
+ * will check permissions when we perform the op.
+ */
+ if ((mask & MAY_WRITE) && !(mask & MAY_READ))
+ goto out;
+ }
+
+force_lookup:
+ if (!NFS_PROTO(inode)->access)
+ goto out_notsup;
+
+ /* Always try fast lookups first */
+ rcu_read_lock();
+ cred = rpc_lookup_cred_nonblock();
+ if (!IS_ERR(cred))
+ res = nfs_do_access(inode, cred, mask|MAY_NOT_BLOCK);
+ else
+ res = PTR_ERR(cred);
+ rcu_read_unlock();
+ if (res == -ECHILD && !(mask & MAY_NOT_BLOCK)) {
+ /* Fast lookup failed, try the slow way */
+ cred = rpc_lookup_cred();
+ if (!IS_ERR(cred)) {
+ res = nfs_do_access(inode, cred, mask);
+ put_rpccred(cred);
+ } else
+ res = PTR_ERR(cred);
+ }
+out:
+ if (!res && (mask & MAY_EXEC))
+ res = nfs_execute_ok(inode, mask);
+
+ dfprintk(VFS, "NFS: permission(%s/%lu), mask=0x%x, res=%d\n",
+ inode->i_sb->s_id, inode->i_ino, mask, res);
+ return res;
+out_notsup:
+ if (mask & MAY_NOT_BLOCK)
+ return -ECHILD;
+
+ res = nfs_revalidate_inode(NFS_SERVER(inode), inode);
+ if (res == 0)
+ res = generic_permission(inode, mask);
+ goto out;
+}
+EXPORT_SYMBOL_GPL(nfs_permission);
+
+/*
+ * Local variables:
+ * version-control: t
+ * kept-new-versions: 5
+ * End:
+ */