nfsd: move most of nfsfh.h to fs/nfsd

[safe/jmp/linux-2.6] / fs / anon_inodes.c

diff --git a/fs/anon_inodes.c b/fs/anon_inodes.c
index 1a4eee6..2ca7a7c 100644 (file)
--- a/fs/anon_inodes.c
+++ b/fs/anon_inodes.c
@@ -8,8 +8,10 @@
  *
  */
 
+#include <linux/cred.h>
 #include <linux/file.h>
 #include <linux/poll.h>
+#include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/init.h>
 #include <linux/fs.h>
@@ -48,10 +50,23 @@ static struct file_system_type anon_inode_fs_type = {
        .get_sb         = anon_inodefs_get_sb,
        .kill_sb        = kill_anon_super,
 };
-static struct dentry_operations anon_inodefs_dentry_operations = {
+static const struct dentry_operations anon_inodefs_dentry_operations = {
        .d_delete       = anon_inodefs_delete_dentry,
 };
 
+/*
+ * nop .set_page_dirty method so that people can use .page_mkwrite on
+ * anon inodes.
+ */
+static int anon_set_page_dirty(struct page *page)
+{
+       return 0;
+};
+
+static const struct address_space_operations anon_aops = {
+       .set_page_dirty = anon_set_page_dirty,
+};
+
 /**
  * anon_inode_getfd - creates a new file instance by hooking it up to an
  *                    anonymous inode, and a dentry that describe the "class"
@@ -64,25 +79,24 @@ static struct dentry_operations anon_inodefs_dentry_operations = {
  *
  * Creates a new file by hooking it on a single inode. This is useful for files
  * that do not need to have a full-fledged inode in order to operate correctly.
- * All the files created with anon_inode_getfd() will share a single inode,
+ * All the files created with anon_inode_getfile() will share a single inode,
  * hence saving memory and avoiding code duplication for the file/inode/dentry
- * setup.  Returns new descriptor or -error.
+ * setup.  Returns the newly created file* or an error pointer.
  */
-int anon_inode_getfd(const char *name, const struct file_operations *fops,
-                    void *priv, int flags)
+struct file *anon_inode_getfile(const char *name,
+                               const struct file_operations *fops,
+                               void *priv, int flags)
 {
        struct qstr this;
        struct dentry *dentry;
        struct file *file;
-       int error, fd;
+       int error;
 
        if (IS_ERR(anon_inode_inode))
-               return -ENODEV;
+               return ERR_PTR(-ENODEV);
 
-       error = get_unused_fd_flags(flags);
-       if (error < 0)
-               return error;
-       fd = error;
+       if (fops->owner && !try_module_get(fops->owner))
+               return ERR_PTR(-ENOENT);
 
        /*
         * Link the inode to a directory entry by creating a unique name
@@ -94,7 +108,7 @@ int anon_inode_getfd(const char *name, const struct file_operations *fops,
        this.hash = 0;
        dentry = d_alloc(anon_inode_mnt->mnt_sb->s_root, &this);
        if (!dentry)
-               goto err_put_unused_fd;
+               goto err_module;
 
        /*
         * We know the anon_inode inode count is always greater than zero,
@@ -116,16 +130,56 @@ int anon_inode_getfd(const char *name, const struct file_operations *fops,
        file->f_mapping = anon_inode_inode->i_mapping;
 
        file->f_pos = 0;
-       file->f_flags = O_RDWR;
+       file->f_flags = O_RDWR | (flags & O_NONBLOCK);
        file->f_version = 0;
        file->private_data = priv;
 
+       return file;
+
+err_dput:
+       dput(dentry);
+err_module:
+       module_put(fops->owner);
+       return ERR_PTR(error);
+}
+EXPORT_SYMBOL_GPL(anon_inode_getfile);
+
+/**
+ * anon_inode_getfd - creates a new file instance by hooking it up to an
+ *                    anonymous inode, and a dentry that describe the "class"
+ *                    of the file
+ *
+ * @name:    [in]    name of the "class" of the new file
+ * @fops:    [in]    file operations for the new file
+ * @priv:    [in]    private data for the new file (will be file's private_data)
+ * @flags:   [in]    flags
+ *
+ * Creates a new file by hooking it on a single inode. This is useful for files
+ * that do not need to have a full-fledged inode in order to operate correctly.
+ * All the files created with anon_inode_getfd() will share a single inode,
+ * hence saving memory and avoiding code duplication for the file/inode/dentry
+ * setup.  Returns new descriptor or an error code.
+ */
+int anon_inode_getfd(const char *name, const struct file_operations *fops,
+                    void *priv, int flags)
+{
+       int error, fd;
+       struct file *file;
+
+       error = get_unused_fd_flags(flags);
+       if (error < 0)
+               return error;
+       fd = error;
+
+       file = anon_inode_getfile(name, fops, priv, flags);
+       if (IS_ERR(file)) {
+               error = PTR_ERR(file);
+               goto err_put_unused_fd;
+       }
        fd_install(fd, file);
 
        return fd;
 
-err_dput:
-       dput(dentry);
 err_put_unused_fd:
        put_unused_fd(fd);
        return error;
@@ -146,6 +200,8 @@ static struct inode *anon_inode_mkinode(void)
 
        inode->i_fop = &anon_inode_fops;
 
+       inode->i_mapping->a_ops = &anon_aops;
+
        /*
         * Mark the inode dirty from the very beginning,
         * that way it will never be moved to the dirty
@@ -154,8 +210,8 @@ static struct inode *anon_inode_mkinode(void)
         */
        inode->i_state = I_DIRTY;
        inode->i_mode = S_IRUSR | S_IWUSR;
-       inode->i_uid = current->fsuid;
-       inode->i_gid = current->fsgid;
+       inode->i_uid = current_fsuid();
+       inode->i_gid = current_fsgid();
        inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
        return inode;
 }