[PATCH] NFS: Clean up readdir changes.

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

3 files changed, 48 insertions, 39 deletions

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index fceef29c65a3..b38a57e78a63 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -51,8 +51,10 @@ static int nfs_mknod(struct inode *, struct dentry *, int, dev_t);
 static int nfs_rename(struct inode *, struct dentry *,
                       struct inode *, struct dentry *);
 static int nfs_fsync_dir(struct file *, struct dentry *, int);
+static loff_t nfs_llseek_dir(struct file *, loff_t, int);
 
 struct file_operations nfs_dir_operations = {
+        .llseek         = nfs_llseek_dir,
         .read           = generic_read_dir,
         .readdir        = nfs_readdir,
         .open           = nfs_opendir,
@@ -141,9 +143,8 @@ typedef struct {
         struct page     *page;
         unsigned long   page_index;
         u32             *ptr;
-        u64             target_cookie;
-        int             target_index;
-        int             current_index;
+        u64             *dir_cookie;
+        loff_t          current_index;
         struct nfs_entry *entry;
         decode_dirent_t decode;
         int             plus;
@@ -227,7 +228,7 @@ void dir_page_release(nfs_readdir_descriptor_t *desc)
 
 /*
  * Given a pointer to a buffer that has already been filled by a call
- * to readdir, find the next entry with cookie 'desc->target_cookie'.
+ * 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
@@ -241,8 +242,8 @@ int find_dirent(nfs_readdir_descriptor_t *desc)
                         status;
 
         while((status = dir_decode(desc)) == 0) {
-                dfprintk(VFS, "NFS: found cookie %Lu\n", (long long)entry->cookie);
-                if (entry->prev_cookie == desc->target_cookie)
+                dfprintk(VFS, "NFS: found cookie %Lu\n", (unsigned long long)entry->cookie);
+                if (entry->prev_cookie == *desc->dir_cookie)
                         break;
                 if (loop_count++ > 200) {
                         loop_count = 0;
@@ -255,7 +256,7 @@ int find_dirent(nfs_readdir_descriptor_t *desc)
 
 /*
  * Given a pointer to a buffer that has already been filled by a call
- * to readdir, find the entry at offset 'desc->target_index'.
+ * 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
@@ -273,10 +274,10 @@ int find_dirent_index(nfs_readdir_descriptor_t *desc)
                 if (status)
                         break;
 
-                dfprintk(VFS, "NFS: found cookie %Lu at index %d\n", (long long)entry->cookie, desc->current_index);
+                dfprintk(VFS, "NFS: found cookie %Lu at index %Ld\n", (unsigned long long)entry->cookie, desc->current_index);
 
-                if (desc->target_index == desc->current_index) {
-                        desc->target_cookie = entry->cookie;
+                if (desc->file->f_pos == desc->current_index) {
+                        *desc->dir_cookie = entry->cookie;
                         break;
                 }
                 desc->current_index++;
@@ -314,7 +315,7 @@ int find_dirent_page(nfs_readdir_descriptor_t *desc)
         /* NOTE: Someone else may have changed the READDIRPLUS flag */
         desc->page = page;
         desc->ptr = kmap(page);         /* matching kunmap in nfs_do_filldir */
-        if (desc->target_cookie)
+        if (*desc->dir_cookie != 0)
                 status = find_dirent(desc);
         else
                 status = find_dirent_index(desc);
@@ -332,8 +333,8 @@ int find_dirent_page(nfs_readdir_descriptor_t *desc)
  * 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->target_cookie' if non-0,
- * 'desc->target_index' otherwise
+ * The target for the search is '*desc->dir_cookie' if non-0,
+ * 'desc->file->f_pos' otherwise
  */
 static inline
 int readdir_search_pagecache(nfs_readdir_descriptor_t *desc)
@@ -341,18 +342,15 @@ int readdir_search_pagecache(nfs_readdir_descriptor_t *desc)
         int             loop_count = 0;
         int             res;
 
-        if (desc->target_cookie)
-                dfprintk(VFS, "NFS: readdir_search_pagecache() searching for cookie %Lu\n", (long long)desc->target_cookie);
-        else
-                dfprintk(VFS, "NFS: readdir_search_pagecache() searching for cookie number %d\n", desc->target_index);
-
         /* Always search-by-index from the beginning of the cache */
-        if (!(desc->target_cookie)) {
+        if (*desc->dir_cookie == 0) {
+                dfprintk(VFS, "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(VFS, "NFS: readdir_search_pagecache() searching for cookie %Lu\n", (unsigned long long)*desc->dir_cookie);
 
         for (;;) {
                 res = find_dirent_page(desc);
@@ -386,7 +384,6 @@ int nfs_do_filldir(nfs_readdir_descriptor_t *desc, void *dirent,
         struct file     *file = desc->file;
         struct nfs_entry *entry = desc->entry;
         struct dentry   *dentry = NULL;
-        struct nfs_open_context *ctx = file->private_data;
         unsigned long   fileid;
         int             loop_count = 0,
                         res;
@@ -415,7 +412,7 @@ int nfs_do_filldir(nfs_readdir_descriptor_t *desc, void *dirent,
                 if (res < 0)
                         break;
                 file->f_pos++;
-                desc->target_cookie = entry->cookie;
+                *desc->dir_cookie = entry->cookie;
                 if (dir_decode(desc) != 0) {
                         desc->page_index ++;
                         break;
@@ -425,12 +422,10 @@ int nfs_do_filldir(nfs_readdir_descriptor_t *desc, void *dirent,
                         schedule();
                 }
         }
-        ctx->dir_pos        = file->f_pos;
-        ctx->dir_cookie     = desc->target_cookie;
         dir_page_release(desc);
         if (dentry != NULL)
                 dput(dentry);
-        dfprintk(VFS, "NFS: nfs_do_filldir() filling ended @ cookie %Lu; returning = %d\n", (long long)desc->target_cookie, res);
+        dfprintk(VFS, "NFS: nfs_do_filldir() filling ended @ cookie %Lu; returning = %d\n", (unsigned long long)*desc->dir_cookie, res);
         return res;
 }
 
@@ -456,14 +451,14 @@ int uncached_readdir(nfs_readdir_descriptor_t *desc, void *dirent,
         struct page     *page = NULL;
         int             status;
 
-        dfprintk(VFS, "NFS: uncached_readdir() searching for cookie %Lu\n", (long long)desc->target_cookie);
+        dfprintk(VFS, "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->error = NFS_PROTO(inode)->readdir(file->f_dentry, cred, desc->target_cookie,
+        desc->error = NFS_PROTO(inode)->readdir(file->f_dentry, cred, *desc->dir_cookie,
                                                 page,
                                                 NFS_SERVER(inode)->dtsize,
                                                 desc->plus);
@@ -472,7 +467,7 @@ int uncached_readdir(nfs_readdir_descriptor_t *desc, void *dirent,
         desc->ptr = kmap(page);         /* matching kunmap in nfs_do_filldir */
         if (desc->error >= 0) {
                 if ((status = dir_decode(desc)) == 0)
-                        desc->entry->prev_cookie = desc->target_cookie;
+                        desc->entry->prev_cookie = *desc->dir_cookie;
         } else
                 status = -EIO;
         if (status < 0)
@@ -501,7 +496,6 @@ static int nfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
 {
         struct dentry   *dentry = filp->f_dentry;
         struct inode    *inode = dentry->d_inode;
-        struct nfs_open_context *ctx = filp->private_data;
         nfs_readdir_descriptor_t my_desc,
                         *desc = &my_desc;
         struct nfs_entry my_entry;
@@ -519,21 +513,16 @@ static int nfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
 
         /*
          * filp->f_pos points to the dirent entry number.
-         * ctx->dir_pos has the number of the cached cookie.  We have
+         * *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 = &((struct nfs_open_context *)filp->private_data)->dir_cookie;
         desc->decode = NFS_PROTO(inode)->decode_dirent;
         desc->plus = NFS_USE_READDIRPLUS(inode);
-        desc->target_index = filp->f_pos;
-
-        if (filp->f_pos == ctx->dir_pos)
-                desc->target_cookie = ctx->dir_cookie;
-        else
-                desc->target_cookie = 0;
 
         my_entry.cookie = my_entry.prev_cookie = 0;
         my_entry.eof = 0;
@@ -546,7 +535,7 @@ static int nfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
 
                 if (res == -EBADCOOKIE) {
                         /* This means either end of directory */
-                        if (desc->target_cookie && desc->entry->cookie != desc->target_cookie) {
+                        if (*desc->dir_cookie && desc->entry->cookie != *desc->dir_cookie) {
                                 /* Or that the server has 'lost' a cookie */
                                 res = uncached_readdir(desc, dirent, filldir);
                                 if (res >= 0)
@@ -579,6 +568,28 @@ static int nfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
         return 0;
 }
 
+loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int origin)
+{
+        down(&filp->f_dentry->d_inode->i_sem);
+        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;
+                ((struct nfs_open_context *)filp->private_data)->dir_cookie = 0;
+        }
+out:
+        up(&filp->f_dentry->d_inode->i_sem);
+        return offset;
+}
+
 /*
  * All directory operations under NFS are synchronous, so fsync()
  * is a dummy operation.
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 9fa02e7984ac..6300e05e9463 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -891,7 +891,6 @@ struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry, struct rp
                 ctx->state = NULL;
                 ctx->lockowner = current->files;
                 ctx->error = 0;
-                ctx->dir_pos = 0;
                 ctx->dir_cookie = 0;
         }
         return ctx;
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index f810195ef7ad..c90313bfa435 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -85,7 +85,6 @@ struct nfs_open_context {
 
         struct list_head list;
 
-        int dir_pos;            /* Directory cookie cache */
         __u64 dir_cookie;
 };