NFS: add readdir cache array

This patch adds the readdir cache array and functions to retreive the array
stored on a cache page, clear the array by freeing allocated memory, add an
entry to the array, and search the array for a given cookie.

It then modifies readdir to make use of the new cache array.
With the new cache array method, we no longer need some of this code.

Finally, nfs_llseek_dir() will set file->f_pos to a value greater than 0 and
desc->dir_cookie to zero.  When we see this, readdir needs to find the file
at position file->f_pos from the start of the directory.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 309 insertions, 323 deletions

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index a847acf4d3cd..f77243907a08 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -55,6 +55,7 @@ static int nfs_rename(struct inode *, struct dentry *,
                       struct inode *, struct dentry *);
 static int nfs_fsync_dir(struct file *, int);
 static loff_t nfs_llseek_dir(struct file *, loff_t, int);
+static int nfs_readdir_clear_array(struct page*, gfp_t);
 
 const struct file_operations nfs_dir_operations = {
         .llseek         = nfs_llseek_dir,
@@ -80,6 +81,10 @@ const struct inode_operations nfs_dir_inode_operations = {
         .setattr        = nfs_setattr,
 };
 
+const struct address_space_operations nfs_dir_addr_space_ops = {
+        .releasepage = nfs_readdir_clear_array,
+};
+
 #ifdef CONFIG_NFS_V3
 const struct inode_operations nfs3_dir_inode_operations = {
         .create         = nfs_create,
@@ -151,51 +156,188 @@ nfs_opendir(struct inode *inode, struct file *filp)
         return res;
 }
 
+struct nfs_cache_array_entry {
+        u64 cookie;
+        u64 ino;
+        struct qstr string;
+};
+
+struct nfs_cache_array {
+        unsigned int size;
+        int eof_index;
+        u64 last_cookie;
+        struct nfs_cache_array_entry array[0];
+};
+
+#define MAX_READDIR_ARRAY ((PAGE_SIZE - sizeof(struct nfs_cache_array)) / sizeof(struct nfs_cache_array_entry))
+
 typedef __be32 * (*decode_dirent_t)(__be32 *, struct nfs_entry *, int);
 typedef struct {
         struct file     *file;
         struct page     *page;
         unsigned long   page_index;
-        __be32          *ptr;
         u64             *dir_cookie;
         loff_t          current_index;
-        struct nfs_entry *entry;
         decode_dirent_t decode;
-        int             plus;
+
         unsigned long   timestamp;
         unsigned long   gencount;
-        int             timestamp_valid;
+        unsigned int    cache_entry_index;
+        unsigned int    plus:1;
+        unsigned int    eof:1;
 } nfs_readdir_descriptor_t;
 
-/* Now we cache directories properly, by stuffing the dirent
- * data directly in the page cache.
- *
- * Inode invalidation due to refresh etc. takes care of
- * _everything_, no sloppy entry flushing logic, no extraneous
- * copying, network direct to page cache, the way it was meant
- * to be.
- *
- * NOTE: Dirent information verification is done always by the
- *       page-in of the RPC reply, nowhere else, this simplies
- *       things substantially.
+/*
+ * The caller is responsible for calling nfs_readdir_release_array(page)
  */
 static
-int nfs_readdir_filler(nfs_readdir_descriptor_t *desc, struct page *page)
+struct nfs_cache_array *nfs_readdir_get_array(struct page *page)
+{
+        if (page == NULL)
+                return ERR_PTR(-EIO);
+        return (struct nfs_cache_array *)kmap(page);
+}
+
+static
+void nfs_readdir_release_array(struct page *page)
+{
+        kunmap(page);
+}
+
+/*
+ * we are freeing strings created by nfs_add_to_readdir_array()
+ */
+static
+int nfs_readdir_clear_array(struct page *page, gfp_t mask)
+{
+        struct nfs_cache_array *array = nfs_readdir_get_array(page);
+        int i;
+        for (i = 0; i < array->size; i++)
+                kfree(array->array[i].string.name);
+        nfs_readdir_release_array(page);
+        return 0;
+}
+
+/*
+ * 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
+void nfs_readdir_make_qstr(struct qstr *string, const char *name, unsigned int len)
+{
+        string->len = len;
+        string->name = kmemdup(name, len, GFP_KERNEL);
+        string->hash = full_name_hash(string->name, string->len);
+}
+
+static
+int nfs_readdir_add_to_array(struct nfs_entry *entry, struct page *page)
+{
+        struct nfs_cache_array *array = nfs_readdir_get_array(page);
+        if (IS_ERR(array))
+                return PTR_ERR(array);
+        if (array->size >= MAX_READDIR_ARRAY) {
+                nfs_readdir_release_array(page);
+                return -EIO;
+        }
+
+        array->array[array->size].cookie = entry->prev_cookie;
+        array->last_cookie = entry->cookie;
+        array->array[array->size].ino = entry->ino;
+        nfs_readdir_make_qstr(&array->array[array->size].string, entry->name, entry->len);
+        if (entry->eof == 1)
+                array->eof_index = array->size;
+        array->size++;
+        nfs_readdir_release_array(page);
+        return 0;
+}
+
+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;
+                desc->current_index += array->size;
+                return -EAGAIN;
+        }
+
+        index = (unsigned int)diff;
+        *desc->dir_cookie = array->array[index].cookie;
+        desc->cache_entry_index = index;
+        if (index == array->eof_index)
+                desc->eof = 1;
+        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;
+        int status = -EAGAIN;
+
+        for (i = 0; i < array->size; i++) {
+                if (i == array->eof_index) {
+                        desc->eof = 1;
+                        status = -EBADCOOKIE;
+                }
+                if (array->array[i].cookie == *desc->dir_cookie) {
+                        desc->cache_entry_index = i;
+                        status = 0;
+                        break;
+                }
+        }
+
+        return status;
+}
+
+static
+int nfs_readdir_search_array(nfs_readdir_descriptor_t *desc)
+{
+        struct nfs_cache_array *array;
+        int status = -EBADCOOKIE;
+
+        if (desc->dir_cookie == NULL)
+                goto out;
+
+        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);
+
+        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 *xdr_page, nfs_readdir_descriptor_t *desc,
+                        struct nfs_entry *entry, struct file *file, struct inode *inode)
 {
-        struct file     *file = desc->file;
-        struct inode    *inode = file->f_path.dentry->d_inode;
         struct rpc_cred *cred = nfs_file_cred(file);
         unsigned long   timestamp, gencount;
         int             error;
 
-        dfprintk(DIRCACHE, "NFS: %s: reading cookie %Lu into page %lu\n",
-                        __func__, (long long)desc->entry->cookie,
-                        page->index);
-
  again:
         timestamp = jiffies;
         gencount = nfs_inc_attr_generation_counter();
-        error = NFS_PROTO(inode)->readdir(file->f_path.dentry, cred, desc->entry->cookie, page,
+        error = NFS_PROTO(inode)->readdir(file->f_path.dentry, cred, entry->cookie, xdr_page,
                                           NFS_SERVER(inode)->dtsize, desc->plus);
         if (error < 0) {
                 /* We requested READDIRPLUS, but the server doesn't grok it */
@@ -209,190 +351,157 @@ int nfs_readdir_filler(nfs_readdir_descriptor_t *desc, struct page *page)
         }
         desc->timestamp = timestamp;
         desc->gencount = gencount;
-        desc->timestamp_valid = 1;
-        SetPageUptodate(page);
-        /* Ensure consistent page alignment of the data.
-         * Note: assumes we have exclusive access to this mapping either
-         *       through inode->i_mutex or some other mechanism.
-         */
-        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 -EIO;
+error:
+        return error;
 }
 
-static inline
-int dir_decode(nfs_readdir_descriptor_t *desc)
+/* Fill in an entry based on the xdr code stored in desc->page */
+static
+int xdr_decode(nfs_readdir_descriptor_t *desc, struct nfs_entry *entry, __be32 **ptr)
 {
-        __be32  *p = desc->ptr;
-        p = desc->decode(p, desc->entry, desc->plus);
+        __be32  *p = *ptr;
+        p = desc->decode(p, entry, desc->plus);
         if (IS_ERR(p))
                 return PTR_ERR(p);
-        desc->ptr = p;
-        if (desc->timestamp_valid) {
-                desc->entry->fattr->time_start = desc->timestamp;
-                desc->entry->fattr->gencount = desc->gencount;
-        } else
-                desc->entry->fattr->valid &= ~NFS_ATTR_FATTR;
-        return 0;
-}
+        *ptr = p;
 
-static inline
-void dir_page_release(nfs_readdir_descriptor_t *desc)
-{
-        kunmap(desc->page);
-        page_cache_release(desc->page);
-        desc->page = NULL;
-        desc->ptr = NULL;
+        entry->fattr->time_start = desc->timestamp;
+        entry->fattr->gencount = desc->gencount;
+        return 0;
 }
 
-/*
- * Given a pointer to a buffer that has already been filled by a call
- * to readdir, find the next entry with cookie '*desc->dir_cookie'.
- *
- * If the end of the buffer has been reached, return -EAGAIN, if not,
- * return the offset within the buffer of the next entry to be
- * read.
- */
-static inline
-int find_dirent(nfs_readdir_descriptor_t *desc)
+/* Perform conversion from xdr to cache array */
+static
+void nfs_readdir_page_filler(nfs_readdir_descriptor_t *desc, struct nfs_entry *entry,
+                                struct page *xdr_page, struct page *page)
 {
-        struct nfs_entry *entry = desc->entry;
-        int             loop_count = 0,
-                        status;
-
-        while((status = dir_decode(desc)) == 0) {
-                dfprintk(DIRCACHE, "NFS: %s: examining cookie %Lu\n",
-                                __func__, (unsigned long long)entry->cookie);
-                if (entry->prev_cookie == *desc->dir_cookie)
+        __be32 *ptr = kmap(xdr_page);
+        while (xdr_decode(desc, entry, &ptr) == 0) {
+                if (nfs_readdir_add_to_array(entry, page) == -1)
                         break;
-                if (loop_count++ > 200) {
-                        loop_count = 0;
-                        schedule();
-                }
         }
-        return status;
+        kunmap(xdr_page);
 }
 
-/*
- * Given a pointer to a buffer that has already been filled by a call
- * to readdir, find the entry at offset 'desc->file->f_pos'.
- *
- * If the end of the buffer has been reached, return -EAGAIN, if not,
- * return the offset within the buffer of the next entry to be
- * read.
- */
-static inline
-int find_dirent_index(nfs_readdir_descriptor_t *desc)
+static
+int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page, struct inode *inode)
 {
-        struct nfs_entry *entry = desc->entry;
-        int             loop_count = 0,
-                        status;
-
-        for(;;) {
-                status = dir_decode(desc);
-                if (status)
-                        break;
+        struct page *xdr_page;
+        struct nfs_entry entry;
+        struct file     *file = desc->file;
+        struct nfs_cache_array *array;
+        int status = 0;
+
+        entry.prev_cookie = 0;
+        entry.cookie = *desc->dir_cookie;
+        entry.eof = 0;
+        entry.fh = nfs_alloc_fhandle();
+        entry.fattr = nfs_alloc_fattr();
+        if (entry.fh == NULL || entry.fattr == NULL)
+                goto out;
 
-                dfprintk(DIRCACHE, "NFS: found cookie %Lu at index %Ld\n",
-                                (unsigned long long)entry->cookie, desc->current_index);
+        array = nfs_readdir_get_array(page);
+        memset(array, 0, sizeof(struct nfs_cache_array));
+        array->eof_index = -1;
 
-                if (desc->file->f_pos == desc->current_index) {
-                        *desc->dir_cookie = entry->cookie;
+        xdr_page = alloc_page(GFP_KERNEL);
+        if (!xdr_page)
+                goto out_release_array;
+        do {
+                status = nfs_readdir_xdr_filler(xdr_page, desc, &entry, file, inode);
+                if (status < 0)
                         break;
-                }
-                desc->current_index++;
-                if (loop_count++ > 200) {
-                        loop_count = 0;
-                        schedule();
-                }
-        }
+                nfs_readdir_page_filler(desc, &entry, xdr_page, page);
+        } while (array->eof_index < 0 && array->size < MAX_READDIR_ARRAY);
+
+        put_page(xdr_page);
+out_release_array:
+        nfs_readdir_release_array(page);
+out:
+        nfs_free_fattr(entry.fattr);
+        nfs_free_fhandle(entry.fh);
         return status;
 }
 
 /*
- * Find the given page, and call find_dirent() or find_dirent_index in
- * order to try to return the next entry.
+ * 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 inline
-int find_dirent_page(nfs_readdir_descriptor_t *desc)
+static
+int nfs_readdir_filler(nfs_readdir_descriptor_t *desc, struct page* page)
 {
         struct inode    *inode = desc->file->f_path.dentry->d_inode;
-        struct page     *page;
-        int             status;
 
-        dfprintk(DIRCACHE, "NFS: %s: searching page %ld for target %Lu\n",
-                        __func__, desc->page_index,
-                        (long long) *desc->dir_cookie);
+        if (nfs_readdir_xdr_to_array(desc, page, inode) == -1)
+                goto error;
+        SetPageUptodate(page);
 
-        /* If we find the page in the page_cache, we cannot be sure
-         * how fresh the data is, so we will ignore readdir_plus attributes.
-         */
-        desc->timestamp_valid = 0;
-        page = read_cache_page(inode->i_mapping, desc->page_index,
-                               (filler_t *)nfs_readdir_filler, desc);
-        if (IS_ERR(page)) {
-                status = PTR_ERR(page);
-                goto out;
+        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 -EIO;
+}
 
-        /* NOTE: Someone else may have changed the READDIRPLUS flag */
-        desc->page = page;
-        desc->ptr = kmap(page);         /* matching kunmap in nfs_do_filldir */
-        if (*desc->dir_cookie != 0)
-                status = find_dirent(desc);
-        else
-                status = find_dirent_index(desc);
-        if (status < 0)
-                dir_page_release(desc);
- out:
-        dfprintk(DIRCACHE, "NFS: %s: returns %d\n", __func__, status);
-        return status;
+static
+void cache_page_release(nfs_readdir_descriptor_t *desc)
+{
+        page_cache_release(desc->page);
+        desc->page = NULL;
+}
+
+static
+struct page *get_cache_page(nfs_readdir_descriptor_t *desc)
+{
+        struct page *page;
+        page = read_cache_page(desc->file->f_path.dentry->d_inode->i_mapping,
+                        desc->page_index, (filler_t *)nfs_readdir_filler, desc);
+        if (IS_ERR(page))
+                desc->eof = 1;
+        return page;
 }
 
 /*
- * Recurse through the page cache pages, and return a
- * filled nfs_entry structure of the next directory entry if possible.
- *
- * The target for the search is '*desc->dir_cookie' if non-0,
- * 'desc->file->f_pos' otherwise
+ * 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)
+                return 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             loop_count = 0;
-        int             res;
-
-        /* Always search-by-index from the beginning of the cache */
-        if (*desc->dir_cookie == 0) {
-                dfprintk(DIRCACHE, "NFS: readdir_search_pagecache() searching for offset %Ld\n",
-                                (long long)desc->file->f_pos);
-                desc->page_index = 0;
-                desc->entry->cookie = desc->entry->prev_cookie = 0;
-                desc->entry->eof = 0;
-                desc->current_index = 0;
-        } else
-                dfprintk(DIRCACHE, "NFS: readdir_search_pagecache() searching for cookie %Lu\n",
-                                (unsigned long long)*desc->dir_cookie);
+        int res = -EAGAIN;
+        desc->page_index = 0;
 
-        for (;;) {
-                res = find_dirent_page(desc);
+        if (*desc->dir_cookie == 0)
+                desc->cache_entry_index = 0;
+
+        while (1) {
+                res = find_cache_page(desc);
                 if (res != -EAGAIN)
                         break;
-                /* Align to beginning of next page */
-                desc->page_index ++;
-                if (loop_count++ > 200) {
-                        loop_count = 0;
-                        schedule();
-                }
+                desc->page_index++;
         }
-
-        dfprintk(DIRCACHE, "NFS: %s: returns %d\n", __func__, res);
         return res;
 }
 
@@ -401,8 +510,6 @@ static inline unsigned int dt_type(struct inode *inode)
         return (inode->i_mode >> 12) & 15;
 }
 
-static struct dentry *nfs_readdir_lookup(nfs_readdir_descriptor_t *desc);
-
 /*
  * Once we've found the start of the dirent within a page: fill 'er up...
  */
@@ -411,49 +518,36 @@ int nfs_do_filldir(nfs_readdir_descriptor_t *desc, void *dirent,
                    filldir_t filldir)
 {
         struct file     *file = desc->file;
-        struct nfs_entry *entry = desc->entry;
-        struct dentry   *dentry = NULL;
-        u64             fileid;
-        int             loop_count = 0,
-                        res;
-
-        dfprintk(DIRCACHE, "NFS: nfs_do_filldir() filling starting @ cookie %Lu\n",
-                        (unsigned long long)entry->cookie);
-
-        for(;;) {
-                unsigned d_type = DT_UNKNOWN;
-                /* Note: entry->prev_cookie contains the cookie for
-                 *       retrieving the current dirent on the server */
-                fileid = entry->ino;
-
-                /* Get a dentry if we have one */
-                if (dentry != NULL)
-                        dput(dentry);
-                dentry = nfs_readdir_lookup(desc);
-
-                /* Use readdirplus info */
-                if (dentry != NULL && dentry->d_inode != NULL) {
-                        d_type = dt_type(dentry->d_inode);
-                        fileid = NFS_FILEID(dentry->d_inode);
-                }
+        int i = 0;
+        int res = 0;
+        struct nfs_cache_array *array = NULL;
+        unsigned int d_type = DT_UNKNOWN;
+        struct dentry *dentry = NULL;
 
-                res = filldir(dirent, entry->name, entry->len, 
-                              file->f_pos, nfs_compat_user_ino64(fileid),
-                              d_type);
+        array = nfs_readdir_get_array(desc->page);
+
+        for (i = desc->cache_entry_index; i < array->size; i++) {
+                d_type = DT_UNKNOWN;
+
+                res = filldir(dirent, array->array[i].string.name,
+                        array->array[i].string.len, file->f_pos,
+                        nfs_compat_user_ino64(array->array[i].ino), d_type);
                 if (res < 0)
                         break;
                 file->f_pos++;
-                *desc->dir_cookie = entry->cookie;
-                if (dir_decode(desc) != 0) {
-                        desc->page_index ++;
+                desc->cache_entry_index = i;
+                if (i < (array->size-1))
+                        *desc->dir_cookie = array->array[i+1].cookie;
+                else
+                        *desc->dir_cookie = array->last_cookie;
+                if (i == array->eof_index) {
+                        desc->eof = 1;
                         break;
                 }
-                if (loop_count++ > 200) {
-                        loop_count = 0;
-                        schedule();
-                }
         }
-        dir_page_release(desc);
+
+        nfs_readdir_release_array(desc->page);
+        cache_page_release(desc);
         if (dentry != NULL)
                 dput(dentry);
         dfprintk(DIRCACHE, "NFS: nfs_do_filldir() filling ended @ cookie %Lu; returning = %d\n",
@@ -477,12 +571,9 @@ static inline
 int uncached_readdir(nfs_readdir_descriptor_t *desc, void *dirent,
                      filldir_t filldir)
 {
-        struct file     *file = desc->file;
-        struct inode    *inode = file->f_path.dentry->d_inode;
-        struct rpc_cred *cred = nfs_file_cred(file);
         struct page     *page = NULL;
         int             status;
-        unsigned long   timestamp, gencount;
+        struct inode *inode = desc->file->f_path.dentry->d_inode;
 
         dfprintk(DIRCACHE, "NFS: uncached_readdir() searching for cookie %Lu\n",
                         (unsigned long long)*desc->dir_cookie);
@@ -492,38 +583,21 @@ int uncached_readdir(nfs_readdir_descriptor_t *desc, void *dirent,
                 status = -ENOMEM;
                 goto out;
         }
-        timestamp = jiffies;
-        gencount = nfs_inc_attr_generation_counter();
-        status = NFS_PROTO(inode)->readdir(file->f_path.dentry, cred,
-                                                *desc->dir_cookie, page,
-                                                NFS_SERVER(inode)->dtsize,
-                                                desc->plus);
-        desc->page = page;
-        desc->ptr = kmap(page);         /* matching kunmap in nfs_do_filldir */
-        if (status >= 0) {
-                desc->timestamp = timestamp;
-                desc->gencount = gencount;
-                desc->timestamp_valid = 1;
-                if ((status = dir_decode(desc)) == 0)
-                        desc->entry->prev_cookie = *desc->dir_cookie;
-        } else
+
+        if (nfs_readdir_xdr_to_array(desc, page, inode) == -1) {
                 status = -EIO;
-        if (status < 0)
                 goto out_release;
+        }
 
+        desc->page = page;
         status = nfs_do_filldir(desc, dirent, filldir);
 
-        /* Reset read descriptor so it searches the page cache from
-         * the start upon the next call to readdir_search_pagecache() */
-        desc->page_index = 0;
-        desc->entry->cookie = desc->entry->prev_cookie = 0;
-        desc->entry->eof = 0;
  out:
         dfprintk(DIRCACHE, "NFS: %s: returns %d\n",
                         __func__, status);
         return status;
  out_release:
-        dir_page_release(desc);
+        cache_page_release(desc);
         goto out;
 }
 
@@ -537,7 +611,6 @@ static int nfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
         struct inode    *inode = dentry->d_inode;
         nfs_readdir_descriptor_t my_desc,
                         *desc = &my_desc;
-        struct nfs_entry my_entry;
         int res = -ENOMEM;
 
         dfprintk(FILE, "NFS: readdir(%s/%s) starting at cookie %llu\n",
@@ -558,26 +631,17 @@ static int nfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
         desc->decode = NFS_PROTO(inode)->decode_dirent;
         desc->plus = NFS_USE_READDIRPLUS(inode);
 
-        my_entry.cookie = my_entry.prev_cookie = 0;
-        my_entry.eof = 0;
-        my_entry.fh = nfs_alloc_fhandle();
-        my_entry.fattr = nfs_alloc_fattr();
-        if (my_entry.fh == NULL || my_entry.fattr == NULL)
-                goto out_alloc_failed;
-
-        desc->entry = &my_entry;
-
         nfs_block_sillyrename(dentry);
         res = nfs_revalidate_mapping(inode, filp->f_mapping);
         if (res < 0)
                 goto out;
 
-        while(!desc->entry->eof) {
+        while (desc->eof != 1) {
                 res = readdir_search_pagecache(desc);
 
                 if (res == -EBADCOOKIE) {
                         /* This means either end of directory */
-                        if (*desc->dir_cookie && desc->entry->cookie != *desc->dir_cookie) {
+                        if (*desc->dir_cookie && desc->eof == 0) {
                                 /* Or that the server has 'lost' a cookie */
                                 res = uncached_readdir(desc, dirent, filldir);
                                 if (res >= 0)
@@ -590,7 +654,7 @@ static int nfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
                         clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags);
                         nfs_zap_caches(inode);
                         desc->plus = 0;
-                        desc->entry->eof = 0;
+                        desc->eof = 0;
                         continue;
                 }
                 if (res < 0)
@@ -606,9 +670,6 @@ out:
         nfs_unblock_sillyrename(dentry);
         if (res > 0)
                 res = 0;
-out_alloc_failed:
-        nfs_free_fattr(my_entry.fattr);
-        nfs_free_fhandle(my_entry.fh);
         dfprintk(FILE, "NFS: readdir(%s/%s) returns %d\n",
                         dentry->d_parent->d_name.name, dentry->d_name.name,
                         res);
@@ -1292,81 +1353,6 @@ out_err:
 
 #endif /* CONFIG_NFSV4 */
 
-static struct dentry *nfs_readdir_lookup(nfs_readdir_descriptor_t *desc)
-{
-        struct dentry *parent = desc->file->f_path.dentry;
-        struct inode *dir = parent->d_inode;
-        struct nfs_entry *entry = desc->entry;
-        struct dentry *dentry, *alias;
-        struct qstr name = {
-                .name = entry->name,
-                .len = entry->len,
-        };
-        struct inode *inode;
-        unsigned long verf = nfs_save_change_attribute(dir);
-
-        switch (name.len) {
-                case 2:
-                        if (name.name[0] == '.' && name.name[1] == '.')
-                                return dget_parent(parent);
-                        break;
-                case 1:
-                        if (name.name[0] == '.')
-                                return dget(parent);
-        }
-
-        spin_lock(&dir->i_lock);
-        if (NFS_I(dir)->cache_validity & NFS_INO_INVALID_DATA) {
-                spin_unlock(&dir->i_lock);
-                return NULL;
-        }
-        spin_unlock(&dir->i_lock);
-
-        name.hash = full_name_hash(name.name, name.len);
-        dentry = d_lookup(parent, &name);
-        if (dentry != NULL) {
-                /* Is this a positive dentry that matches the readdir info? */
-                if (dentry->d_inode != NULL &&
-                                (NFS_FILEID(dentry->d_inode) == entry->ino ||
-                                d_mountpoint(dentry))) {
-                        if (!desc->plus || entry->fh->size == 0)
-                                return dentry;
-                        if (nfs_compare_fh(NFS_FH(dentry->d_inode),
-                                                entry->fh) == 0)
-                                goto out_renew;
-                }
-                /* No, so d_drop to allow one to be created */
-                d_drop(dentry);
-                dput(dentry);
-        }
-        if (!desc->plus || !(entry->fattr->valid & NFS_ATTR_FATTR))
-                return NULL;
-        if (name.len > NFS_SERVER(dir)->namelen)
-                return NULL;
-        /* Note: caller is already holding the dir->i_mutex! */
-        dentry = d_alloc(parent, &name);
-        if (dentry == NULL)
-                return NULL;
-        dentry->d_op = NFS_PROTO(dir)->dentry_ops;
-        inode = nfs_fhget(dentry->d_sb, entry->fh, entry->fattr);
-        if (IS_ERR(inode)) {
-                dput(dentry);
-                return NULL;
-        }
-
-        alias = d_materialise_unique(dentry, inode);
-        if (alias != NULL) {
-                dput(dentry);
-                if (IS_ERR(alias))
-                        return NULL;
-                dentry = alias;
-        }
-
-out_renew:
-        nfs_set_verifier(dentry, verf);
-        return dentry;
-}
-
 /*
  * Code common to create, mkdir, and mknod.
  */