zte's code,first commit
Change-Id: I9a04da59e459a9bc0d67f101f700d9d7dc8d681b
diff --git a/ap/os/linux/linux-3.4.x/fs/nfs/dir.c b/ap/os/linux/linux-3.4.x/fs/nfs/dir.c
new file mode 100644
index 0000000..a0daac7
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/fs/nfs/dir.c
@@ -0,0 +1,2363 @@
+/*
+ * 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/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/sched.h>
+#include <linux/kmemleak.h>
+#include <linux/xattr.h>
+
+#include "delegation.h"
+#include "iostat.h"
+#include "internal.h"
+#include "fscache.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 *, void *, filldir_t);
+static struct dentry *nfs_lookup(struct inode *, struct dentry *, struct nameidata *);
+static int nfs_create(struct inode *, struct dentry *, umode_t, struct nameidata *);
+static int nfs_mkdir(struct inode *, struct dentry *, umode_t);
+static int nfs_rmdir(struct inode *, struct dentry *);
+static int nfs_unlink(struct inode *, struct dentry *);
+static int nfs_symlink(struct inode *, struct dentry *, const char *);
+static int nfs_link(struct dentry *, struct inode *, struct dentry *);
+static int nfs_mknod(struct inode *, struct dentry *, umode_t, dev_t);
+static int nfs_rename(struct inode *, struct dentry *,
+ struct inode *, struct dentry *);
+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,
+ .readdir = nfs_readdir,
+ .open = nfs_opendir,
+ .release = nfs_closedir,
+ .fsync = nfs_fsync_dir,
+};
+
+const struct inode_operations nfs_dir_inode_operations = {
+ .create = nfs_create,
+ .lookup = nfs_lookup,
+ .link = nfs_link,
+ .unlink = nfs_unlink,
+ .symlink = nfs_symlink,
+ .mkdir = nfs_mkdir,
+ .rmdir = nfs_rmdir,
+ .mknod = nfs_mknod,
+ .rename = nfs_rename,
+ .permission = nfs_permission,
+ .getattr = nfs_getattr,
+ .setattr = nfs_setattr,
+};
+
+const struct address_space_operations nfs_dir_aops = {
+ .freepage = nfs_readdir_clear_array,
+};
+
+#ifdef CONFIG_NFS_V3
+const struct inode_operations nfs3_dir_inode_operations = {
+ .create = nfs_create,
+ .lookup = nfs_lookup,
+ .link = nfs_link,
+ .unlink = nfs_unlink,
+ .symlink = nfs_symlink,
+ .mkdir = nfs_mkdir,
+ .rmdir = nfs_rmdir,
+ .mknod = nfs_mknod,
+ .rename = nfs_rename,
+ .permission = nfs_permission,
+ .getattr = nfs_getattr,
+ .setattr = nfs_setattr,
+ .listxattr = nfs3_listxattr,
+ .getxattr = nfs3_getxattr,
+ .setxattr = nfs3_setxattr,
+ .removexattr = nfs3_removexattr,
+};
+#endif /* CONFIG_NFS_V3 */
+
+#ifdef CONFIG_NFS_V4
+
+static struct dentry *nfs_atomic_lookup(struct inode *, struct dentry *, struct nameidata *);
+static int nfs_open_create(struct inode *dir, struct dentry *dentry, umode_t mode, struct nameidata *nd);
+const struct inode_operations nfs4_dir_inode_operations = {
+ .create = nfs_open_create,
+ .lookup = nfs_atomic_lookup,
+ .link = nfs_link,
+ .unlink = nfs_unlink,
+ .symlink = nfs_symlink,
+ .mkdir = nfs_mkdir,
+ .rmdir = nfs_rmdir,
+ .mknod = nfs_mknod,
+ .rename = nfs_rename,
+ .permission = nfs_permission,
+ .getattr = nfs_getattr,
+ .setattr = nfs_setattr,
+ .getxattr = generic_getxattr,
+ .setxattr = generic_setxattr,
+ .listxattr = generic_listxattr,
+ .removexattr = generic_removexattr,
+};
+
+#endif /* CONFIG_NFS_V4 */
+
+static struct nfs_open_dir_context *alloc_nfs_open_dir_context(struct inode *dir, struct rpc_cred *cred)
+{
+ struct nfs_open_dir_context *ctx;
+ ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
+ if (ctx != NULL) {
+ ctx->duped = 0;
+ ctx->attr_gencount = NFS_I(dir)->attr_gencount;
+ ctx->dir_cookie = 0;
+ ctx->dup_cookie = 0;
+ ctx->cred = get_rpccred(cred);
+ return ctx;
+ }
+ return ERR_PTR(-ENOMEM);
+}
+
+static void put_nfs_open_dir_context(struct nfs_open_dir_context *ctx)
+{
+ 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(%s/%s)\n",
+ filp->f_path.dentry->d_parent->d_name.name,
+ filp->f_path.dentry->d_name.name);
+
+ 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(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 *, int);
+typedef struct {
+ struct file *file;
+ struct page *page;
+ 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;
+ unsigned int plus:1;
+ unsigned int eof:1;
+} nfs_readdir_descriptor_t;
+
+/*
+ * The caller is responsible for calling nfs_readdir_release_array(page)
+ */
+static
+struct nfs_cache_array *nfs_readdir_get_array(struct page *page)
+{
+ void *ptr;
+ if (page == NULL)
+ return ERR_PTR(-EIO);
+ ptr = kmap(page);
+ if (ptr == NULL)
+ return ERR_PTR(-ENOMEM);
+ return ptr;
+}
+
+static
+void nfs_readdir_release_array(struct page *page)
+{
+ kunmap(page);
+}
+
+/*
+ * 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);
+ 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(name, len);
+ return 0;
+}
+
+static
+int nfs_readdir_add_to_array(struct nfs_entry *entry, struct page *page)
+{
+ struct nfs_cache_array *array = nfs_readdir_get_array(page);
+ struct nfs_cache_array_entry *cache_entry;
+ int ret;
+
+ if (IS_ERR(array))
+ return PTR_ERR(array);
+
+ 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:
+ nfs_readdir_release_array(page);
+ return ret;
+}
+
+static
+int nfs_readdir_search_for_pos(struct nfs_cache_array *array, nfs_readdir_descriptor_t *desc)
+{
+ loff_t diff = desc->file->f_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
+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(desc->file->f_path.dentry->d_inode);
+ struct nfs_open_dir_context *ctx = desc->file->private_data;
+
+ new_pos = desc->current_index + i;
+ if (ctx->attr_gencount != nfsi->attr_gencount
+ || (nfsi->cache_validity & (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA))) {
+ ctx->duped = 0;
+ ctx->attr_gencount = nfsi->attr_gencount;
+ } else if (new_pos < desc->file->f_pos) {
+ if (ctx->duped > 0
+ && ctx->dup_cookie == *desc->dir_cookie) {
+ if (printk_ratelimit()) {
+ pr_notice("NFS: directory %s/%s contains a readdir loop."
+ "Please contact your server vendor. "
+ "The file: %s has duplicate cookie %llu\n",
+ desc->file->f_dentry->d_parent->d_name.name,
+ desc->file->f_dentry->d_name.name,
+ array->array[i].string.name,
+ *desc->dir_cookie);
+ }
+ status = -ELOOP;
+ goto out;
+ }
+ ctx->dup_cookie = *desc->dir_cookie;
+ ctx->duped = -1;
+ }
+ desc->file->f_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 = nfs_readdir_get_array(desc->page);
+ if (IS_ERR(array)) {
+ status = PTR_ERR(array);
+ goto out;
+ }
+
+ 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++;
+ }
+ nfs_readdir_release_array(desc->page);
+out:
+ 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->f_path.dentry, 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 = 0;
+ 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;
+}
+
+static
+int nfs_same_file(struct dentry *dentry, struct nfs_entry *entry)
+{
+ if (dentry->d_inode == NULL)
+ goto different;
+ if (nfs_compare_fh(entry->fh, NFS_FH(dentry->d_inode)) != 0)
+ goto different;
+ return 1;
+different:
+ return 0;
+}
+
+static
+void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry)
+{
+ struct qstr filename = {
+ .len = entry->len,
+ .name = entry->name,
+ };
+ struct dentry *dentry;
+ struct dentry *alias;
+ struct inode *dir = parent->d_inode;
+ struct inode *inode;
+
+ if (filename.name[0] == '.') {
+ if (filename.len == 1)
+ return;
+ if (filename.len == 2 && filename.name[1] == '.')
+ return;
+ }
+ filename.hash = full_name_hash(filename.name, filename.len);
+
+ dentry = d_lookup(parent, &filename);
+ if (dentry != NULL) {
+ if (nfs_same_file(dentry, entry)) {
+ nfs_refresh_inode(dentry->d_inode, entry->fattr);
+ goto out;
+ } else {
+ d_drop(dentry);
+ dput(dentry);
+ }
+ }
+
+ dentry = d_alloc(parent, &filename);
+ if (dentry == NULL)
+ return;
+
+ inode = nfs_fhget(dentry->d_sb, entry->fh, entry->fattr);
+ if (IS_ERR(inode))
+ goto out;
+
+ alias = d_materialise_unique(dentry, inode);
+ if (IS_ERR(alias))
+ goto out;
+ else if (alias) {
+ nfs_set_verifier(alias, nfs_save_change_attribute(dir));
+ dput(alias);
+ } else
+ 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;
+
+ 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 != 0)
+ nfs_prime_dcache(desc->file->f_path.dentry, entry);
+
+ status = nfs_readdir_add_to_array(entry, page);
+ if (status != 0)
+ break;
+ } while (!entry->eof);
+
+ if (count == 0 || (status == -EBADCOOKIE && entry->eof != 0)) {
+ array = nfs_readdir_get_array(page);
+ if (!IS_ERR(array)) {
+ array->eof_index = array->size;
+ status = 0;
+ nfs_readdir_release_array(page);
+ } else
+ status = PTR_ERR(array);
+ }
+
+ put_page(scratch);
+ return status;
+}
+
+static
+void nfs_readdir_free_pagearray(struct page **pages, unsigned int npages)
+{
+ unsigned int i;
+ for (i = 0; i < npages; i++)
+ put_page(pages[i]);
+}
+
+static
+void nfs_readdir_free_large_page(void *ptr, struct page **pages,
+ unsigned int npages)
+{
+ nfs_readdir_free_pagearray(pages, npages);
+}
+
+/*
+ * nfs_readdir_large_page will allocate pages that must be freed with a call
+ * to nfs_readdir_free_large_page
+ */
+static
+int nfs_readdir_large_page(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_pagearray(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];
+ void *pages_ptr = NULL;
+ struct nfs_entry entry;
+ struct file *file = desc->file;
+ struct nfs_cache_array *array;
+ int status = -ENOMEM;
+ unsigned int array_size = ARRAY_SIZE(pages);
+
+ 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;
+
+ array = nfs_readdir_get_array(page);
+ if (IS_ERR(array)) {
+ status = PTR_ERR(array);
+ goto out;
+ }
+ memset(array, 0, sizeof(struct nfs_cache_array));
+ array->eof_index = -1;
+
+ status = nfs_readdir_large_page(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_large_page(pages_ptr, pages, array_size);
+out_release_array:
+ nfs_readdir_release_array(page);
+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(nfs_readdir_descriptor_t *desc, struct page* page)
+{
+ struct inode *inode = desc->file->f_path.dentry->d_inode;
+ 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:
+ unlock_page(page);
+ return ret;
+}
+
+static
+void cache_page_release(nfs_readdir_descriptor_t *desc)
+{
+ if (!desc->page->mapping)
+ nfs_readdir_clear_array(desc->page);
+ page_cache_release(desc->page);
+ desc->page = NULL;
+}
+
+static
+struct page *get_cache_page(nfs_readdir_descriptor_t *desc)
+{
+ return read_cache_page(desc->file->f_path.dentry->d_inode->i_mapping,
+ desc->page_index, (filler_t *)nfs_readdir_filler, desc);
+}
+
+/*
+ * Returns 0 if desc->dir_cookie was found on page desc->page_index
+ */
+static
+int find_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 = nfs_readdir_search_array(desc);
+ if (res != 0)
+ 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_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, void *dirent,
+ filldir_t filldir)
+{
+ 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 = nfs_readdir_get_array(desc->page);
+ if (IS_ERR(array)) {
+ res = PTR_ERR(array);
+ goto out;
+ }
+
+ for (i = desc->cache_entry_index; i < array->size; i++) {
+ struct nfs_cache_array_entry *ent;
+
+ ent = &array->array[i];
+ if (filldir(dirent, ent->string.name, ent->string.len,
+ file->f_pos, nfs_compat_user_ino64(ent->ino),
+ ent->d_type) < 0) {
+ desc->eof = 1;
+ break;
+ }
+ file->f_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;
+
+ nfs_readdir_release_array(desc->page);
+out:
+ cache_page_release(desc);
+ 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, void *dirent,
+ filldir_t filldir)
+{
+ struct page *page = NULL;
+ int status;
+ struct inode *inode = desc->file->f_path.dentry->d_inode;
+ 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, dirent, filldir);
+
+ out:
+ dfprintk(DIRCACHE, "NFS: %s: returns %d\n",
+ __func__, status);
+ return status;
+ out_release:
+ cache_page_release(desc);
+ goto out;
+}
+
+/* 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 *filp, void *dirent, filldir_t filldir)
+{
+ struct dentry *dentry = filp->f_path.dentry;
+ struct inode *inode = dentry->d_inode;
+ nfs_readdir_descriptor_t my_desc,
+ *desc = &my_desc;
+ struct nfs_open_dir_context *dir_ctx = filp->private_data;
+ int res;
+
+ dfprintk(FILE, "NFS: readdir(%s/%s) starting at cookie %llu\n",
+ dentry->d_parent->d_name.name, dentry->d_name.name,
+ (long long)filp->f_pos);
+ nfs_inc_stats(inode, NFSIOS_VFSGETDENTS);
+
+ /*
+ * filp->f_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 = filp;
+ desc->dir_cookie = &dir_ctx->dir_cookie;
+ desc->decode = NFS_PROTO(inode)->decode_dirent;
+ desc->plus = NFS_USE_READDIRPLUS(inode);
+
+ nfs_block_sillyrename(dentry);
+ res = nfs_revalidate_mapping(inode, filp->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, dirent, filldir);
+ 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 = 0;
+ desc->eof = 0;
+ continue;
+ }
+ if (res < 0)
+ break;
+
+ res = nfs_do_filldir(desc, dirent, filldir);
+ if (res < 0)
+ break;
+ } while (!desc->eof);
+out:
+ nfs_unblock_sillyrename(dentry);
+ if (res > 0)
+ res = 0;
+ dfprintk(FILE, "NFS: readdir(%s/%s) returns %d\n",
+ dentry->d_parent->d_name.name, dentry->d_name.name,
+ res);
+ return res;
+}
+
+static loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int origin)
+{
+ struct dentry *dentry = filp->f_path.dentry;
+ struct inode *inode = dentry->d_inode;
+ struct nfs_open_dir_context *dir_ctx = filp->private_data;
+
+ dfprintk(FILE, "NFS: llseek dir(%s/%s, %lld, %d)\n",
+ dentry->d_parent->d_name.name,
+ dentry->d_name.name,
+ offset, origin);
+
+ mutex_lock(&inode->i_mutex);
+ switch (origin) {
+ 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:
+ mutex_unlock(&inode->i_mutex);
+ 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 dentry *dentry = filp->f_path.dentry;
+ struct inode *inode = dentry->d_inode;
+
+ dfprintk(FILE, "NFS: fsync dir(%s/%s) datasync %d\n",
+ dentry->d_parent->d_name.name, dentry->d_name.name,
+ datasync);
+
+ mutex_lock(&inode->i_mutex);
+ nfs_inc_stats(dentry->d_inode, NFSIOS_VFSFSYNC);
+ mutex_unlock(&inode->i_mutex);
+ 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++;
+}
+
+/*
+ * 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.
+ */
+static int nfs_check_verifier(struct inode *dir, struct dentry *dentry)
+{
+ 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_revalidate_inode(NFS_SERVER(dir), dir) < 0)
+ return 0;
+ if (!nfs_verify_change_attribute(dir, dentry->d_time))
+ return 0;
+ return 1;
+}
+
+/*
+ * Return the intent data that applies to this particular path component
+ *
+ * Note that the current set of intents only apply to the very last
+ * component of the path and none of them is set before that last
+ * component.
+ */
+static inline unsigned int nfs_lookup_check_intent(struct nameidata *nd,
+ unsigned int mask)
+{
+ return nd->flags & mask;
+}
+
+/*
+ * 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, struct nameidata *nd)
+{
+ if (NFS_PROTO(dir)->version == 2)
+ return 0;
+ return nd && nfs_lookup_check_intent(nd, 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 inline
+int nfs_lookup_verify_inode(struct inode *inode, struct nameidata *nd)
+{
+ struct nfs_server *server = NFS_SERVER(inode);
+
+ if (IS_AUTOMOUNT(inode))
+ return 0;
+ if (nd != NULL) {
+ /* VFS wants an on-the-wire revalidation */
+ if (nd->flags & LOOKUP_REVAL)
+ goto out_force;
+ /* This is an open(2) */
+ if (nfs_lookup_check_intent(nd, LOOKUP_OPEN) != 0 &&
+ !(server->flags & NFS_MOUNT_NOCTO) &&
+ (S_ISREG(inode->i_mode) ||
+ S_ISDIR(inode->i_mode)))
+ goto out_force;
+ return 0;
+ }
+ return nfs_revalidate_inode(server, inode);
+out_force:
+ return __nfs_revalidate_inode(server, inode);
+}
+
+/*
+ * 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.
+ */
+static inline
+int nfs_neg_need_reval(struct inode *dir, struct dentry *dentry,
+ struct nameidata *nd)
+{
+ /* Don't revalidate a negative dentry if we're creating a new file */
+ if (nd != NULL && nfs_lookup_check_intent(nd, LOOKUP_CREATE) != 0)
+ return 0;
+ if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG)
+ return 1;
+ return !nfs_check_verifier(dir, dentry);
+}
+
+/*
+ * 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_lookup_revalidate(struct dentry *dentry, struct nameidata *nd)
+{
+ struct inode *dir;
+ struct inode *inode;
+ struct dentry *parent;
+ struct nfs_fh *fhandle = NULL;
+ struct nfs_fattr *fattr = NULL;
+ int error;
+
+ if (nd && (nd->flags & LOOKUP_RCU))
+ return -ECHILD;
+
+ parent = dget_parent(dentry);
+ dir = parent->d_inode;
+ nfs_inc_stats(dir, NFSIOS_DENTRYREVALIDATE);
+ inode = dentry->d_inode;
+
+ if (!inode) {
+ if (nfs_neg_need_reval(dir, dentry, nd))
+ goto out_bad;
+ goto out_valid;
+ }
+
+ if (is_bad_inode(inode)) {
+ dfprintk(LOOKUPCACHE, "%s: %s/%s has dud inode\n",
+ __func__, dentry->d_parent->d_name.name,
+ dentry->d_name.name);
+ goto out_bad;
+ }
+
+ if (nfs_have_delegation(inode, FMODE_READ))
+ goto out_set_verifier;
+
+ /* Force a full look up iff the parent directory has changed */
+ if (!nfs_is_exclusive_create(dir, nd) && nfs_check_verifier(dir, dentry)) {
+ if (nfs_lookup_verify_inode(inode, nd))
+ goto out_zap_parent;
+ goto out_valid;
+ }
+
+ if (NFS_STALE(inode))
+ goto out_bad;
+
+ error = -ENOMEM;
+ fhandle = nfs_alloc_fhandle();
+ fattr = nfs_alloc_fattr();
+ if (fhandle == NULL || fattr == NULL)
+ goto out_error;
+
+ error = NFS_PROTO(dir)->lookup(NFS_SERVER(dir)->client, dir, &dentry->d_name, fhandle, fattr);
+ if (error)
+ goto out_bad;
+ if (nfs_compare_fh(NFS_FH(inode), fhandle))
+ goto out_bad;
+ if ((error = nfs_refresh_inode(inode, fattr)) != 0)
+ goto out_bad;
+
+ nfs_free_fattr(fattr);
+ nfs_free_fhandle(fhandle);
+out_set_verifier:
+ nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
+ out_valid:
+ dput(parent);
+ dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is valid\n",
+ __func__, dentry->d_parent->d_name.name,
+ dentry->d_name.name);
+ return 1;
+out_zap_parent:
+ nfs_zap_caches(dir);
+ out_bad:
+ nfs_mark_for_revalidate(dir);
+ if (inode && S_ISDIR(inode->i_mode)) {
+ /* Purge readdir caches. */
+ nfs_zap_caches(inode);
+ /* If we have submounts, don't unhash ! */
+ if (have_submounts(dentry))
+ goto out_valid;
+ if (dentry->d_flags & DCACHE_DISCONNECTED)
+ goto out_valid;
+ shrink_dcache_parent(dentry);
+ }
+ d_drop(dentry);
+ nfs_free_fattr(fattr);
+ nfs_free_fhandle(fhandle);
+ dput(parent);
+ dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is invalid\n",
+ __func__, dentry->d_parent->d_name.name,
+ dentry->d_name.name);
+ return 0;
+out_error:
+ nfs_free_fattr(fattr);
+ nfs_free_fhandle(fhandle);
+ dput(parent);
+ dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) lookup returned error %d\n",
+ __func__, dentry->d_parent->d_name.name,
+ dentry->d_name.name, error);
+ 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(%s/%s, %x)\n",
+ dentry->d_parent->d_name.name, dentry->d_name.name,
+ dentry->d_flags);
+
+ /* Unhash any dentry with a stale inode */
+ if (dentry->d_inode != NULL && NFS_STALE(dentry->d_inode))
+ 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_delete = nfs_dentry_delete,
+ .d_iput = nfs_dentry_iput,
+ .d_automount = nfs_d_automount,
+ .d_release = nfs_d_release,
+};
+
+static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
+{
+ struct dentry *res;
+ struct dentry *parent;
+ struct inode *inode = NULL;
+ struct nfs_fh *fhandle = NULL;
+ struct nfs_fattr *fattr = NULL;
+ int error;
+
+ dfprintk(VFS, "NFS: lookup(%s/%s)\n",
+ dentry->d_parent->d_name.name, dentry->d_name.name);
+ nfs_inc_stats(dir, NFSIOS_VFSLOOKUP);
+
+ res = ERR_PTR(-ENAMETOOLONG);
+ if (dentry->d_name.len > NFS_SERVER(dir)->namelen)
+ goto out;
+
+ /*
+ * If we're doing an exclusive create, optimize away the lookup
+ * but don't hash the dentry.
+ */
+ if (nfs_is_exclusive_create(dir, nd)) {
+ d_instantiate(dentry, NULL);
+ res = NULL;
+ goto out;
+ }
+
+ res = ERR_PTR(-ENOMEM);
+ fhandle = nfs_alloc_fhandle();
+ fattr = nfs_alloc_fattr();
+ if (fhandle == NULL || fattr == NULL)
+ goto out;
+
+ parent = dentry->d_parent;
+ /* Protect against concurrent sillydeletes */
+ nfs_block_sillyrename(parent);
+ error = NFS_PROTO(dir)->lookup(NFS_SERVER(dir)->client, dir, &dentry->d_name, fhandle, fattr);
+ if (error == -ENOENT)
+ goto no_entry;
+ if (error < 0) {
+ res = ERR_PTR(error);
+ goto out_unblock_sillyrename;
+ }
+ inode = nfs_fhget(dentry->d_sb, fhandle, fattr);
+ res = ERR_CAST(inode);
+ if (IS_ERR(res))
+ goto out_unblock_sillyrename;
+
+no_entry:
+ res = d_materialise_unique(dentry, inode);
+ if (res != NULL) {
+ if (IS_ERR(res))
+ goto out_unblock_sillyrename;
+ dentry = res;
+ }
+ nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
+out_unblock_sillyrename:
+ nfs_unblock_sillyrename(parent);
+out:
+ nfs_free_fattr(fattr);
+ nfs_free_fhandle(fhandle);
+ return res;
+}
+
+#ifdef CONFIG_NFS_V4
+static int nfs_open_revalidate(struct dentry *, struct nameidata *);
+
+const struct dentry_operations nfs4_dentry_operations = {
+ .d_revalidate = nfs_open_revalidate,
+ .d_delete = nfs_dentry_delete,
+ .d_iput = nfs_dentry_iput,
+ .d_automount = nfs_d_automount,
+ .d_release = nfs_d_release,
+};
+
+/*
+ * Use intent information to determine whether we need to substitute
+ * the NFSv4-style stateful OPEN for the LOOKUP call
+ */
+static int is_atomic_open(struct nameidata *nd)
+{
+ if (nd == NULL || nfs_lookup_check_intent(nd, LOOKUP_OPEN) == 0)
+ return 0;
+ /* NFS does not (yet) have a stateful open for directories */
+ if (nd->flags & LOOKUP_DIRECTORY)
+ return 0;
+ /* Are we trying to write to a read only partition? */
+ if (__mnt_is_readonly(nd->path.mnt) &&
+ (nd->intent.open.flags & (O_CREAT|O_TRUNC|O_ACCMODE)))
+ return 0;
+ return 1;
+}
+
+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)
+{
+ return alloc_nfs_open_context(dentry, flags_to_mode(open_flags));
+}
+
+static int do_open(struct inode *inode, struct file *filp)
+{
+ nfs_fscache_set_inode_cookie(inode, filp);
+ return 0;
+}
+
+static int nfs_intent_set_file(struct nameidata *nd, struct nfs_open_context *ctx)
+{
+ struct file *filp;
+ int ret = 0;
+
+ /* If the open_intent is for execute, we have an extra check to make */
+ if (ctx->mode & FMODE_EXEC) {
+ ret = nfs_may_open(ctx->dentry->d_inode,
+ ctx->cred,
+ nd->intent.open.flags);
+ if (ret < 0)
+ goto out;
+ }
+ filp = lookup_instantiate_filp(nd, ctx->dentry, do_open);
+ if (IS_ERR(filp))
+ ret = PTR_ERR(filp);
+ else
+ nfs_file_set_open_context(filp, ctx);
+out:
+ put_nfs_open_context(ctx);
+ return ret;
+}
+
+static struct dentry *nfs_atomic_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
+{
+ struct nfs_open_context *ctx;
+ struct iattr attr;
+ struct dentry *res = NULL;
+ struct inode *inode;
+ int open_flags;
+ int err;
+
+ dfprintk(VFS, "NFS: atomic_lookup(%s/%ld), %s\n",
+ dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
+
+ /* Check that we are indeed trying to open this file */
+ if (!is_atomic_open(nd))
+ goto no_open;
+
+ if (dentry->d_name.len > NFS_SERVER(dir)->namelen) {
+ res = ERR_PTR(-ENAMETOOLONG);
+ goto out;
+ }
+
+ /* Let vfs_create() deal with O_EXCL. Instantiate, but don't hash
+ * the dentry. */
+ if (nd->flags & LOOKUP_EXCL) {
+ d_instantiate(dentry, NULL);
+ goto out;
+ }
+
+ open_flags = nd->intent.open.flags;
+ attr.ia_valid = ATTR_OPEN;
+
+ ctx = create_nfs_open_context(dentry, open_flags);
+ res = ERR_CAST(ctx);
+ if (IS_ERR(ctx))
+ goto out;
+
+ if (nd->flags & LOOKUP_CREATE) {
+ attr.ia_mode = nd->intent.open.create_mode;
+ attr.ia_valid |= ATTR_MODE;
+ attr.ia_mode &= ~current_umask();
+ } else
+ open_flags &= ~(O_EXCL | O_CREAT);
+
+ if (open_flags & O_TRUNC) {
+ attr.ia_valid |= ATTR_SIZE;
+ attr.ia_size = 0;
+ }
+
+ /* Open the file on the server */
+ nfs_block_sillyrename(dentry->d_parent);
+ inode = NFS_PROTO(dir)->open_context(dir, ctx, open_flags, &attr);
+ if (IS_ERR(inode)) {
+ nfs_unblock_sillyrename(dentry->d_parent);
+ put_nfs_open_context(ctx);
+ switch (PTR_ERR(inode)) {
+ /* Make a negative dentry */
+ case -ENOENT:
+ d_add(dentry, NULL);
+ res = NULL;
+ goto out;
+ /* This turned out not to be a regular file */
+ case -EISDIR:
+ case -ENOTDIR:
+ goto no_open;
+ case -ELOOP:
+ if (!(nd->intent.open.flags & O_NOFOLLOW))
+ goto no_open;
+ /* case -EINVAL: */
+ default:
+ res = ERR_CAST(inode);
+ goto out;
+ }
+ }
+ res = d_add_unique(dentry, inode);
+ nfs_unblock_sillyrename(dentry->d_parent);
+ if (res != NULL) {
+ dput(ctx->dentry);
+ ctx->dentry = dget(res);
+ dentry = res;
+ }
+ err = nfs_intent_set_file(nd, ctx);
+ if (err < 0) {
+ if (res != NULL)
+ dput(res);
+ return ERR_PTR(err);
+ }
+out:
+ nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
+ return res;
+no_open:
+ return nfs_lookup(dir, dentry, nd);
+}
+
+static int nfs_open_revalidate(struct dentry *dentry, struct nameidata *nd)
+{
+ struct dentry *parent = NULL;
+ struct inode *inode;
+ struct inode *dir;
+ struct nfs_open_context *ctx;
+ struct iattr attr;
+ int openflags, ret = 0;
+
+ if (nd && (nd->flags & LOOKUP_RCU))
+ return -ECHILD;
+
+ inode = dentry->d_inode;
+ if (!is_atomic_open(nd) || d_mountpoint(dentry))
+ goto no_open;
+
+ parent = dget_parent(dentry);
+ dir = parent->d_inode;
+
+ /* We can't create new files in nfs_open_revalidate(), so we
+ * optimize away revalidation of negative dentries.
+ */
+ if (inode == NULL) {
+ if (!nfs_neg_need_reval(dir, dentry, nd))
+ ret = 1;
+ goto out;
+ }
+
+ /* NFS only supports OPEN on regular files */
+ if (!S_ISREG(inode->i_mode))
+ goto no_open_dput;
+ openflags = nd->intent.open.flags;
+ /* We cannot do exclusive creation on a positive dentry */
+ if ((openflags & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL))
+ goto no_open_dput;
+ /* We can't create new files here */
+ openflags &= ~(O_CREAT|O_EXCL);
+
+ ctx = create_nfs_open_context(dentry, openflags);
+ ret = PTR_ERR(ctx);
+ if (IS_ERR(ctx))
+ goto out;
+
+ attr.ia_valid = ATTR_OPEN;
+ if (openflags & O_TRUNC) {
+ attr.ia_valid |= ATTR_SIZE;
+ attr.ia_size = 0;
+ nfs_wb_all(inode);
+ }
+
+ /*
+ * Note: we're not holding inode->i_mutex and so may be racing with
+ * operations that change the directory. We therefore save the
+ * change attribute *before* we do the RPC call.
+ */
+ inode = NFS_PROTO(dir)->open_context(dir, ctx, openflags, &attr);
+ if (IS_ERR(inode)) {
+ ret = PTR_ERR(inode);
+ switch (ret) {
+ case -EPERM:
+ case -EACCES:
+ case -EDQUOT:
+ case -ENOSPC:
+ case -EROFS:
+ goto out_put_ctx;
+ default:
+ goto out_drop;
+ }
+ }
+ iput(inode);
+ if (inode != dentry->d_inode)
+ goto out_drop;
+
+ nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
+ ret = nfs_intent_set_file(nd, ctx);
+ if (ret >= 0)
+ ret = 1;
+out:
+ dput(parent);
+ return ret;
+out_drop:
+ d_drop(dentry);
+ ret = 0;
+out_put_ctx:
+ put_nfs_open_context(ctx);
+ goto out;
+
+no_open_dput:
+ dput(parent);
+no_open:
+ return nfs_lookup_revalidate(dentry, nd);
+}
+
+static int nfs_open_create(struct inode *dir, struct dentry *dentry,
+ umode_t mode, struct nameidata *nd)
+{
+ struct nfs_open_context *ctx = NULL;
+ struct iattr attr;
+ int error;
+ int open_flags = O_CREAT|O_EXCL;
+
+ dfprintk(VFS, "NFS: create(%s/%ld), %s\n",
+ dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
+
+ attr.ia_mode = mode;
+ attr.ia_valid = ATTR_MODE;
+
+ if (nd)
+ open_flags = nd->intent.open.flags;
+
+ ctx = create_nfs_open_context(dentry, open_flags);
+ error = PTR_ERR(ctx);
+ if (IS_ERR(ctx))
+ goto out_err_drop;
+
+ error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags, ctx);
+ if (error != 0)
+ goto out_put_ctx;
+ if (nd) {
+ error = nfs_intent_set_file(nd, ctx);
+ if (error < 0)
+ goto out_err;
+ } else {
+ put_nfs_open_context(ctx);
+ }
+ return 0;
+out_put_ctx:
+ put_nfs_open_context(ctx);
+out_err_drop:
+ d_drop(dentry);
+out_err:
+ return error;
+}
+
+#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 dentry *parent = dget_parent(dentry);
+ struct inode *dir = parent->d_inode;
+ struct inode *inode;
+ int error = -EACCES;
+
+ d_drop(dentry);
+
+ /* We may have been initialized further down */
+ if (dentry->d_inode)
+ goto out;
+ if (fhandle->size == 0) {
+ error = NFS_PROTO(dir)->lookup(NFS_SERVER(dir)->client, dir, &dentry->d_name, fhandle, fattr);
+ 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);
+ if (error < 0)
+ goto out_error;
+ }
+ inode = nfs_fhget(dentry->d_sb, fhandle, fattr);
+ 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;
+}
+
+/*
+ * 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.
+ */
+static int nfs_create(struct inode *dir, struct dentry *dentry,
+ umode_t mode, struct nameidata *nd)
+{
+ struct iattr attr;
+ int error;
+ int open_flags = O_CREAT|O_EXCL;
+
+ dfprintk(VFS, "NFS: create(%s/%ld), %s\n",
+ dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
+
+ attr.ia_mode = mode;
+ attr.ia_valid = ATTR_MODE;
+
+ if (nd)
+ open_flags = nd->intent.open.flags;
+
+ error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags, NULL);
+ if (error != 0)
+ goto out_err;
+ return 0;
+out_err:
+ d_drop(dentry);
+ return error;
+}
+
+/*
+ * See comments for nfs_proc_create regarding failed operations.
+ */
+static 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/%ld), %s\n",
+ dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
+
+ if (!new_valid_dev(rdev))
+ return -EINVAL;
+
+ attr.ia_mode = mode;
+ attr.ia_valid = ATTR_MODE;
+
+ status = NFS_PROTO(dir)->mknod(dir, dentry, &attr, rdev);
+ if (status != 0)
+ goto out_err;
+ return 0;
+out_err:
+ d_drop(dentry);
+ return status;
+}
+
+/*
+ * See comments for nfs_proc_create regarding failed operations.
+ */
+static int nfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
+{
+ struct iattr attr;
+ int error;
+
+ dfprintk(VFS, "NFS: mkdir(%s/%ld), %s\n",
+ dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
+
+ attr.ia_valid = ATTR_MODE;
+ attr.ia_mode = mode | S_IFDIR;
+
+ error = NFS_PROTO(dir)->mkdir(dir, dentry, &attr);
+ if (error != 0)
+ goto out_err;
+ return 0;
+out_err:
+ d_drop(dentry);
+ return error;
+}
+
+static void nfs_dentry_handle_enoent(struct dentry *dentry)
+{
+ if (dentry->d_inode != NULL && !d_unhashed(dentry))
+ d_delete(dentry);
+}
+
+static int nfs_rmdir(struct inode *dir, struct dentry *dentry)
+{
+ int error;
+
+ dfprintk(VFS, "NFS: rmdir(%s/%ld), %s\n",
+ dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
+
+ error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name);
+ /* Ensure the VFS deletes this inode */
+ if (error == 0 && dentry->d_inode != NULL)
+ clear_nlink(dentry->d_inode);
+ else if (error == -ENOENT)
+ nfs_dentry_handle_enoent(dentry);
+
+ return error;
+}
+
+/*
+ * 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 = dentry->d_parent->d_inode;
+ struct inode *inode = dentry->d_inode;
+ int error = -EBUSY;
+
+ dfprintk(VFS, "NFS: safe_remove(%s/%s)\n",
+ dentry->d_parent->d_name.name, dentry->d_name.name);
+
+ /* If the dentry was sillyrenamed, we simply call d_delete() */
+ if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
+ error = 0;
+ goto out;
+ }
+
+ if (inode != NULL) {
+ nfs_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);
+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.
+ */
+static int nfs_unlink(struct inode *dir, struct dentry *dentry)
+{
+ int error;
+ int need_rehash = 0;
+
+ dfprintk(VFS, "NFS: unlink(%s/%ld, %s)\n", dir->i_sb->s_id,
+ dir->i_ino, dentry->d_name.name);
+
+ spin_lock(&dentry->d_lock);
+ if (dentry->d_count > 1) {
+ spin_unlock(&dentry->d_lock);
+ /* Start asynchronous writeout of the inode */
+ write_inode_now(dentry->d_inode, 0);
+ error = nfs_sillyrename(dir, dentry);
+ return error;
+ }
+ 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);
+ return error;
+}
+
+/*
+ * 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.
+ */
+static int nfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
+{
+ struct pagevec lru_pvec;
+ struct page *page;
+ char *kaddr;
+ struct iattr attr;
+ unsigned int pathlen = strlen(symname);
+ int error;
+
+ dfprintk(VFS, "NFS: symlink(%s/%ld, %s, %s)\n", dir->i_sb->s_id,
+ dir->i_ino, dentry->d_name.name, symname);
+
+ if (pathlen > PAGE_SIZE)
+ return -ENAMETOOLONG;
+
+ attr.ia_mode = S_IFLNK | S_IRWXUGO;
+ attr.ia_valid = ATTR_MODE;
+
+ page = alloc_page(GFP_HIGHUSER);
+ if (!page)
+ return -ENOMEM;
+
+ kaddr = kmap_atomic(page);
+ memcpy(kaddr, symname, pathlen);
+ if (pathlen < PAGE_SIZE)
+ memset(kaddr + pathlen, 0, PAGE_SIZE - pathlen);
+ kunmap_atomic(kaddr);
+
+ error = NFS_PROTO(dir)->symlink(dir, dentry, page, pathlen, &attr);
+ if (error != 0) {
+ dfprintk(VFS, "NFS: symlink(%s/%ld, %s, %s) error %d\n",
+ dir->i_sb->s_id, dir->i_ino,
+ dentry->d_name.name, 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.
+ */
+ pagevec_init(&lru_pvec, 0);
+ if (!add_to_page_cache(page, dentry->d_inode->i_mapping, 0,
+ GFP_KERNEL)) {
+ pagevec_add(&lru_pvec, page);
+ pagevec_lru_add_file(&lru_pvec);
+ SetPageUptodate(page);
+ unlock_page(page);
+ } else
+ __free_page(page);
+
+ return 0;
+}
+
+static int
+nfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
+{
+ struct inode *inode = old_dentry->d_inode;
+ int error;
+
+ dfprintk(VFS, "NFS: link(%s/%s -> %s/%s)\n",
+ old_dentry->d_parent->d_name.name, old_dentry->d_name.name,
+ dentry->d_parent->d_name.name, dentry->d_name.name);
+
+ nfs_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);
+ }
+ return error;
+}
+
+/*
+ * 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.
+ */
+static int nfs_rename(struct inode *old_dir, struct dentry *old_dentry,
+ struct inode *new_dir, struct dentry *new_dentry)
+{
+ struct inode *old_inode = old_dentry->d_inode;
+ struct inode *new_inode = new_dentry->d_inode;
+ struct dentry *dentry = NULL, *rehash = NULL;
+ int error = -EBUSY;
+
+ dfprintk(VFS, "NFS: rename(%s/%s -> %s/%s, ct=%d)\n",
+ old_dentry->d_parent->d_name.name, old_dentry->d_name.name,
+ new_dentry->d_parent->d_name.name, new_dentry->d_name.name,
+ new_dentry->d_count);
+
+ /*
+ * 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 (new_dentry->d_count > 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_inode_return_delegation(old_inode);
+ if (new_inode != NULL)
+ nfs_inode_return_delegation(new_inode);
+
+ error = NFS_PROTO(old_dir)->rename(old_dir, &old_dentry->d_name,
+ new_dir, &new_dentry->d_name);
+ nfs_mark_for_revalidate(old_inode);
+out:
+ if (rehash)
+ d_rehash(rehash);
+ if (!error) {
+ if (new_inode != NULL)
+ nfs_drop_nlink(new_inode);
+ d_move(old_dentry, new_dentry);
+ nfs_set_verifier(new_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;
+}
+
+static DEFINE_SPINLOCK(nfs_access_lru_lock);
+static LIST_HEAD(nfs_access_lru_list);
+static atomic_long_t nfs_access_nr_entries;
+
+static void nfs_access_free_entry(struct nfs_access_entry *entry)
+{
+ put_rpccred(entry->cred);
+ kfree(entry);
+ smp_mb__before_atomic_dec();
+ atomic_long_dec(&nfs_access_nr_entries);
+ smp_mb__after_atomic_dec();
+}
+
+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);
+ }
+}
+
+int nfs_access_cache_shrinker(struct shrinker *shrink,
+ struct shrink_control *sc)
+{
+ LIST_HEAD(head);
+ struct nfs_inode *nfsi, *next;
+ struct nfs_access_entry *cache;
+ int nr_to_scan = sc->nr_to_scan;
+ gfp_t gfp_mask = sc->gfp_mask;
+
+ if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL)
+ return (nr_to_scan == 0) ? 0 : -1;
+
+ 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);
+ 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_clear_bit();
+ clear_bit(NFS_INO_ACL_LRU_SET, &nfsi->flags);
+ smp_mb__after_clear_bit();
+ }
+ spin_unlock(&inode->i_lock);
+ }
+ spin_unlock(&nfs_access_lru_lock);
+ nfs_access_free_list(&head);
+ return (atomic_long_read(&nfs_access_nr_entries) / 100) * sysctl_vfs_cache_pressure;
+}
+
+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);
+}
+
+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)
+{
+ struct nfs_inode *nfsi = NFS_I(inode);
+ struct nfs_access_entry *cache;
+ int err = -ENOENT;
+
+ spin_lock(&inode->i_lock);
+ if (nfsi->cache_validity & NFS_INO_INVALID_ACCESS)
+ goto out_zap;
+ cache = nfs_access_search_rbtree(inode, cred);
+ if (cache == NULL)
+ goto out;
+ if (!nfs_have_delegated_attributes(inode) &&
+ !time_in_range_open(jiffies, cache->jiffies, cache->jiffies + nfsi->attrtimeo))
+ goto out_stale;
+ res->jiffies = cache->jiffies;
+ 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_stale:
+ rb_erase(&cache->rb_node, &nfsi->access_cache);
+ list_del(&cache->lru);
+ spin_unlock(&inode->i_lock);
+ nfs_access_free_entry(cache);
+ return -ENOENT;
+out_zap:
+ spin_unlock(&inode->i_lock);
+ nfs_access_zap_cache(inode);
+ return -ENOENT;
+}
+
+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);
+}
+
+static 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->jiffies = set->jiffies;
+ cache->cred = get_rpccred(set->cred);
+ cache->mask = set->mask;
+
+ nfs_access_add_rbtree(inode, cache);
+
+ /* Update accounting */
+ smp_mb__before_atomic_inc();
+ atomic_long_inc(&nfs_access_nr_entries);
+ smp_mb__after_atomic_inc();
+
+ /* 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);
+ }
+}
+
+static int nfs_do_access(struct inode *inode, struct rpc_cred *cred, int mask)
+{
+ struct nfs_access_entry cache;
+ int status;
+
+ status = nfs_access_get_cached(inode, cred, &cache);
+ if (status == 0)
+ goto out;
+
+ /* Be clever: ask server to check for all possible rights */
+ cache.mask = MAY_EXEC | MAY_WRITE | MAY_READ;
+ cache.cred = cred;
+ cache.jiffies = jiffies;
+ 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);
+ }
+ return status;
+ }
+ nfs_access_add_cache(inode, &cache);
+out:
+ if ((mask & ~cache.mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0)
+ return 0;
+ return -EACCES;
+}
+
+static int nfs_open_permission_mask(int openflags)
+{
+ int mask = 0;
+
+ if ((openflags & O_ACCMODE) != O_WRONLY)
+ mask |= MAY_READ;
+ if ((openflags & O_ACCMODE) != O_RDONLY)
+ mask |= MAY_WRITE;
+ if (openflags & __FMODE_EXEC)
+ mask |= MAY_EXEC;
+ 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));
+}
+
+int nfs_permission(struct inode *inode, int mask)
+{
+ struct rpc_cred *cred;
+ int res = 0;
+
+ if (mask & MAY_NOT_BLOCK)
+ return -ECHILD;
+
+ 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:
+ /* NFSv4 has atomic_open... */
+ if (nfs_server_capable(inode, NFS_CAP_ATOMIC_OPEN)
+ && (mask & MAY_OPEN)
+ && !(mask & MAY_EXEC))
+ goto out;
+ 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;
+
+ 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) && !execute_ok(inode))
+ res = -EACCES;
+
+ dfprintk(VFS, "NFS: permission(%s/%ld), mask=0x%x, res=%d\n",
+ inode->i_sb->s_id, inode->i_ino, mask, res);
+ return res;
+out_notsup:
+ res = nfs_revalidate_inode(NFS_SERVER(inode), inode);
+ if (res == 0)
+ res = generic_permission(inode, mask);
+ goto out;
+}
+
+/*
+ * Local variables:
+ * version-control: t
+ * kept-new-versions: 5
+ * End:
+ */