Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (25 commits)
  cifs: remove unnecessary dentry_unhash on rmdir/rename_dir
  ocfs2: remove unnecessary dentry_unhash on rmdir/rename_dir
  exofs: remove unnecessary dentry_unhash on rmdir/rename_dir
  nfs: remove unnecessary dentry_unhash on rmdir/rename_dir
  ext2: remove unnecessary dentry_unhash on rmdir/rename_dir
  ext3: remove unnecessary dentry_unhash on rmdir/rename_dir
  ext4: remove unnecessary dentry_unhash on rmdir/rename_dir
  btrfs: remove unnecessary dentry_unhash in rmdir/rename_dir
  ceph: remove unnecessary dentry_unhash calls
  vfs: clean up vfs_rename_other
  vfs: clean up vfs_rename_dir
  vfs: clean up vfs_rmdir
  vfs: fix vfs_rename_dir for FS_RENAME_DOES_D_MOVE filesystems
  libfs: drop unneeded dentry_unhash
  vfs: update dentry_unhash() comment
  vfs: push dentry_unhash on rename_dir into file systems
  vfs: push dentry_unhash on rmdir into file systems
  vfs: remove dget() from dentry_unhash()
  vfs: dentry_unhash immediately prior to rmdir
  vfs: Block mmapped writes while the fs is frozen
  ...

fs/9p/vfs_inode.c

@@ -814,6 +814,7 @@ int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
 
 int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
 {
+	dentry_unhash(d);
 	return v9fs_remove(i, d, 1);
 }
 
@@ -839,6 +840,9 @@ v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	struct p9_fid *newdirfid;
 	struct p9_wstat wstat;
 
+	if (new_dentry->d_inode && S_ISDIR(new_dentry->d_inode->i_mode))
+		dentry_unhash(new_dentry);
+
 	P9_DPRINTK(P9_DEBUG_VFS, "\n");
 	retval = 0;
 	old_inode = old_dentry->d_inode;

fs/Kconfig

@@ -47,7 +47,7 @@ config FS_POSIX_ACL
 	def_bool n
 
 config EXPORTFS
-	bool
+	tristate
 
 config FILE_LOCKING
 	bool "Enable POSIX file locking API" if EXPERT

fs/affs/namei.c

@@ -320,6 +320,8 @@ affs_rmdir(struct inode *dir, struct dentry *dentry)
 		 dentry->d_inode->i_ino,
 		 (int)dentry->d_name.len, dentry->d_name.name);
 
+	dentry_unhash(dentry);
+
 	return affs_remove_header(dentry);
 }
 
@@ -417,6 +419,9 @@ affs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	struct buffer_head *bh = NULL;
 	int retval;
 
+	if (new_dentry->d_inode && S_ISDIR(new_dentry->d_inode->i_mode))
+		dentry_unhash(new_dentry);
+
 	pr_debug("AFFS: rename(old=%u,\"%*s\" to new=%u,\"%*s\")\n",
 		 (u32)old_dir->i_ino, (int)old_dentry->d_name.len, old_dentry->d_name.name,
 		 (u32)new_dir->i_ino, (int)new_dentry->d_name.len, new_dentry->d_name.name);

fs/afs/dir.c

@@ -845,6 +845,8 @@ static int afs_rmdir(struct inode *dir, struct dentry *dentry)
 	_enter("{%x:%u},{%s}",
 	       dvnode->fid.vid, dvnode->fid.vnode, dentry->d_name.name);
 
+	dentry_unhash(dentry);
+
 	ret = -ENAMETOOLONG;
 	if (dentry->d_name.len >= AFSNAMEMAX)
 		goto error;
@@ -1146,6 +1148,9 @@ static int afs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	struct key *key;
 	int ret;
 
+	if (new_dentry->d_inode && S_ISDIR(new_dentry->d_inode->i_mode))
+		dentry_unhash(new_dentry);
+
 	vnode = AFS_FS_I(old_dentry->d_inode);
 	orig_dvnode = AFS_FS_I(old_dir);
 	new_dvnode = AFS_FS_I(new_dir);

fs/autofs4/root.c

@@ -583,6 +583,8 @@ static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry)
 	if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN))
 		return -EACCES;
 
+	dentry_unhash(dentry);
+
 	if (atomic_dec_and_test(&ino->count)) {
 		p_ino = autofs4_dentry_ino(dentry->d_parent);
 		if (p_ino && dentry->d_parent != dentry)

fs/bfs/dir.c

@@ -224,6 +224,9 @@ static int bfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	struct bfs_sb_info *info;
 	int error = -ENOENT;
 
+	if (new_dentry->d_inode && S_ISDIR(new_dentry->d_inode->i_mode))
+		dentry_unhash(new_dentry);
+
 	old_bh = new_bh = NULL;
 	old_inode = old_dentry->d_inode;
 	if (S_ISDIR(old_inode->i_mode))

fs/buffer.c

@@ -2331,24 +2331,26 @@ EXPORT_SYMBOL(block_commit_write);
  * page lock we can determine safely if the page is beyond EOF. If it is not
  * beyond EOF, then the page is guaranteed safe against truncation until we
  * unlock the page.
+ *
+ * Direct callers of this function should call vfs_check_frozen() so that page
+ * fault does not busyloop until the fs is thawed.
  */
-int
-block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
+int __block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
 			 get_block_t get_block)
 {
 	struct page *page = vmf->page;
 	struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
 	unsigned long end;
 	loff_t size;
-	int ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
+	int ret;
 
 	lock_page(page);
 	size = i_size_read(inode);
 	if ((page->mapping != inode->i_mapping) ||
 	    (page_offset(page) > size)) {
-		/* page got truncated out from underneath us */
-		unlock_page(page);
-		goto out;
+		/* We overload EFAULT to mean page got truncated */
+		ret = -EFAULT;
+		goto out_unlock;
 	}
 
 	/* page is wholly or partially inside EOF */
@@ -2361,18 +2363,41 @@ block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
 	if (!ret)
 		ret = block_commit_write(page, 0, end);
 
-	if (unlikely(ret)) {
+	if (unlikely(ret < 0))
+		goto out_unlock;
+	/*
+	 * Freezing in progress? We check after the page is marked dirty and
+	 * with page lock held so if the test here fails, we are sure freezing
+	 * code will wait during syncing until the page fault is done - at that
+	 * point page will be dirty and unlocked so freezing code will write it
+	 * and writeprotect it again.
+	 */
+	set_page_dirty(page);
+	if (inode->i_sb->s_frozen != SB_UNFROZEN) {
+		ret = -EAGAIN;
+		goto out_unlock;
+	}
+	return 0;
+out_unlock:
 	unlock_page(page);
-		if (ret == -ENOMEM)
-			ret = VM_FAULT_OOM;
-		else /* -ENOSPC, -EIO, etc */
-			ret = VM_FAULT_SIGBUS;
-	} else
-		ret = VM_FAULT_LOCKED;
-
-out:
 	return ret;
 }
+EXPORT_SYMBOL(__block_page_mkwrite);
+
+int block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
+		   get_block_t get_block)
+{
+	int ret;
+	struct super_block *sb = vma->vm_file->f_path.dentry->d_inode->i_sb;
+
+	/*
+	 * This check is racy but catches the common case. The check in
+	 * __block_page_mkwrite() is reliable.
+	 */
+	vfs_check_frozen(sb, SB_FREEZE_WRITE);
+	ret = __block_page_mkwrite(vma, vmf, get_block);
+	return block_page_mkwrite_return(ret);
+}
 EXPORT_SYMBOL(block_page_mkwrite);
 
 /*

fs/coda/dir.c

@@ -336,6 +336,8 @@ static int coda_rmdir(struct inode *dir, struct dentry *de)
 	int len = de->d_name.len;
 	int error;
 
+	dentry_unhash(de);
+
 	error = venus_rmdir(dir->i_sb, coda_i2f(dir), name, len);
 	if (!error) {
 		/* VFS may delete the child */
@@ -359,6 +361,9 @@ static int coda_rename(struct inode *old_dir, struct dentry *old_dentry,
 	int new_length = new_dentry->d_name.len;
 	int error;
 
+	if (new_dentry->d_inode && S_ISDIR(new_dentry->d_inode->i_mode))
+		dentry_unhash(new_dentry);
+
 	error = venus_rename(old_dir->i_sb, coda_i2f(old_dir),
 			     coda_i2f(new_dir), old_length, new_length,
 			     (const char *) old_name, (const char *)new_name);

fs/configfs/dir.c

@@ -1359,6 +1359,8 @@ static int configfs_rmdir(struct inode *dir, struct dentry *dentry)
 	struct module *subsys_owner = NULL, *dead_item_owner = NULL;
 	int ret;
 
+	dentry_unhash(dentry);
+
 	if (dentry->d_parent == configfs_sb->s_root)
 		return -EPERM;
 

fs/ecryptfs/inode.c

@@ -521,6 +521,8 @@ static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
 	struct dentry *lower_dir_dentry;
 	int rc;
 
+	dentry_unhash(dentry);
+
 	lower_dentry = ecryptfs_dentry_to_lower(dentry);
 	dget(dentry);
 	lower_dir_dentry = lock_parent(lower_dentry);
@@ -571,6 +573,9 @@ ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	struct dentry *lower_new_dir_dentry;
 	struct dentry *trap = NULL;
 
+	if (new_dentry->d_inode && S_ISDIR(new_dentry->d_inode->i_mode))
+		dentry_unhash(new_dentry);
+
 	lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
 	lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
 	dget(lower_old_dentry);

fs/fat/namei_msdos.c

@@ -326,6 +326,8 @@ static int msdos_rmdir(struct inode *dir, struct dentry *dentry)
 	struct fat_slot_info sinfo;
 	int err;
 
+	dentry_unhash(dentry);
+
 	lock_super(sb);
 	/*
 	 * Check whether the directory is not in use, then check
@@ -457,6 +459,9 @@ static int do_msdos_rename(struct inode *old_dir, unsigned char *old_name,
 	old_inode = old_dentry->d_inode;
 	new_inode = new_dentry->d_inode;
 
+	if (new_inode && S_ISDIR(new_inode->i_mode))
+		dentry_unhash(new_dentry);
+
 	err = fat_scan(old_dir, old_name, &old_sinfo);
 	if (err) {
 		err = -EIO;

fs/fat/namei_vfat.c

@@ -824,6 +824,8 @@ static int vfat_rmdir(struct inode *dir, struct dentry *dentry)
 	struct fat_slot_info sinfo;
 	int err;
 
+	dentry_unhash(dentry);
+
 	lock_super(sb);
 
 	err = fat_dir_empty(inode);
@@ -931,6 +933,9 @@ static int vfat_rename(struct inode *old_dir, struct dentry *old_dentry,
 	int err, is_dir, update_dotdot, corrupt = 0;
 	struct super_block *sb = old_dir->i_sb;
 
+	if (new_dentry->d_inode && S_ISDIR(new_dentry->d_inode->i_mode))
+		dentry_unhash(new_dentry);
+
 	old_sinfo.bh = sinfo.bh = dotdot_bh = NULL;
 	old_inode = old_dentry->d_inode;
 	new_inode = new_dentry->d_inode;

fs/fuse/dir.c

@@ -667,6 +667,8 @@ static int fuse_rmdir(struct inode *dir, struct dentry *entry)
 	if (IS_ERR(req))
 		return PTR_ERR(req);
 
+	dentry_unhash(entry);
+
 	req->in.h.opcode = FUSE_RMDIR;
 	req->in.h.nodeid = get_node_id(dir);
 	req->in.numargs = 1;
@@ -691,6 +693,10 @@ static int fuse_rename(struct inode *olddir, struct dentry *oldent,
 	struct fuse_rename_in inarg;
 	struct fuse_conn *fc = get_fuse_conn(olddir);
 	struct fuse_req *req = fuse_get_req(fc);
+
+	if (newent->d_inode && S_ISDIR(newent->d_inode->i_mode))
+		dentry_unhash(newent);
+
 	if (IS_ERR(req))
 		return PTR_ERR(req);
 

fs/hfs/dir.c

@@ -253,6 +253,9 @@ static int hfs_remove(struct inode *dir, struct dentry *dentry)
 	struct inode *inode = dentry->d_inode;
 	int res;
 
+	if (S_ISDIR(inode->i_mode))
+		dentry_unhash(dentry);
+
 	if (S_ISDIR(inode->i_mode) && inode->i_size != 2)
 		return -ENOTEMPTY;
 	res = hfs_cat_delete(inode->i_ino, dir, &dentry->d_name);
@@ -283,6 +286,9 @@ static int hfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 
 	/* Unlink destination if it already exists */
 	if (new_dentry->d_inode) {
+		if (S_ISDIR(new_dentry->d_inode->i_mode))
+			dentry_unhash(new_dentry);
+
 		res = hfs_remove(new_dir, new_dentry);
 		if (res)
 			return res;

fs/hfsplus/dir.c

@@ -370,6 +370,8 @@ static int hfsplus_rmdir(struct inode *dir, struct dentry *dentry)
 	struct inode *inode = dentry->d_inode;
 	int res;
 
+	dentry_unhash(dentry);
+
 	if (inode->i_size != 2)
 		return -ENOTEMPTY;
 
@@ -467,10 +469,12 @@ static int hfsplus_rename(struct inode *old_dir, struct dentry *old_dentry,
 
 	/* Unlink destination if it already exists */
 	if (new_dentry->d_inode) {
-		if (S_ISDIR(new_dentry->d_inode->i_mode))
+		if (S_ISDIR(new_dentry->d_inode->i_mode)) {
+			dentry_unhash(new_dentry);
 			res = hfsplus_rmdir(new_dir, new_dentry);
-		else
+		} else {
 			res = hfsplus_unlink(new_dir, new_dentry);
+		}
 		if (res)
 			return res;
 	}

fs/hostfs/hostfs_kern.c

@@ -683,6 +683,8 @@ int hostfs_rmdir(struct inode *ino, struct dentry *dentry)
 	char *file;
 	int err;
 
+	dentry_unhash(dentry);
+
 	if ((file = dentry_name(dentry)) == NULL)
 		return -ENOMEM;
 	err = do_rmdir(file);
@@ -736,6 +738,9 @@ int hostfs_rename(struct inode *from_ino, struct dentry *from,
 	char *from_name, *to_name;
 	int err;
 
+	if (to->d_inode && S_ISDIR(to->d_inode->i_mode))
+		dentry_unhash(to);
+
 	if ((from_name = dentry_name(from)) == NULL)
 		return -ENOMEM;
 	if ((to_name = dentry_name(to)) == NULL) {

fs/hpfs/namei.c

@@ -395,7 +395,6 @@ again:
 
 		dentry_unhash(dentry);
 		if (!d_unhashed(dentry)) {
-			dput(dentry);
 			hpfs_unlock(dir->i_sb);
 			return -ENOSPC;
 		}
@@ -403,7 +402,6 @@ again:
 		    !S_ISREG(inode->i_mode) ||
 		    get_write_access(inode)) {
 			d_rehash(dentry);
-			dput(dentry);
 		} else {
 			struct iattr newattrs;
 			/*printk("HPFS: truncating file before delete.\n");*/
@@ -411,7 +409,6 @@ again:
 			newattrs.ia_valid = ATTR_SIZE | ATTR_CTIME;
 			err = notify_change(dentry, &newattrs);
 			put_write_access(inode);
-			dput(dentry);
 			if (!err)
 				goto again;
 		}
@@ -442,6 +439,8 @@ static int hpfs_rmdir(struct inode *dir, struct dentry *dentry)
 	int err;
 	int r;
 
+	dentry_unhash(dentry);
+
 	hpfs_adjust_length(name, &len);
 	hpfs_lock(dir->i_sb);
 	err = -ENOENT;
@@ -535,6 +534,10 @@ static int hpfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	struct buffer_head *bh;
 	struct fnode *fnode;
 	int err;
+
+	if (new_inode && S_ISDIR(new_inode->i_mode))
+		dentry_unhash(new_dentry);
+
 	if ((err = hpfs_chk_name(new_name, &new_len))) return err;
 	err = 0;
 	hpfs_adjust_length(old_name, &old_len);

fs/jffs2/dir.c

@@ -609,6 +609,8 @@ static int jffs2_rmdir (struct inode *dir_i, struct dentry *dentry)
 	int ret;
 	uint32_t now = get_seconds();
 
+	dentry_unhash(dentry);
+
 	for (fd = f->dents ; fd; fd = fd->next) {
 		if (fd->ino)
 			return -ENOTEMPTY;
@@ -784,6 +786,9 @@ static int jffs2_rename (struct inode *old_dir_i, struct dentry *old_dentry,
 	uint8_t type;
 	uint32_t now;
 
+	if (new_dentry->d_inode && S_ISDIR(new_dentry->d_inode->i_mode))
+		dentry_unhash(new_dentry);
+
 	/* The VFS will check for us and prevent trying to rename a
 	 * file over a directory and vice versa, but if it's a directory,
 	 * the VFS can't check whether the victim is empty. The filesystem

fs/jfs/namei.c

@@ -360,6 +360,8 @@ static int jfs_rmdir(struct inode *dip, struct dentry *dentry)
 
 	jfs_info("jfs_rmdir: dip:0x%p name:%s", dip, dentry->d_name.name);
 
+	dentry_unhash(dentry);
+
 	/* Init inode for quota operations. */
 	dquot_initialize(dip);
 	dquot_initialize(ip);
@@ -1095,6 +1097,9 @@ static int jfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	jfs_info("jfs_rename: %s %s", old_dentry->d_name.name,
 		 new_dentry->d_name.name);
 
+	if (new_dentry->d_inode && S_ISDIR(new_dentry->d_inode->i_mode))
+		dentry_unhash(new_dentry);
+
 	dquot_initialize(old_dir);
 	dquot_initialize(new_dir);
 

fs/logfs/dir.c

@@ -273,6 +273,8 @@ static int logfs_rmdir(struct inode *dir, struct dentry *dentry)
 {
 	struct inode *inode = dentry->d_inode;
 
+	dentry_unhash(dentry);
+
 	if (!logfs_empty_dir(inode))
 		return -ENOTEMPTY;
 
@@ -622,6 +624,9 @@ static int logfs_rename_cross(struct inode *old_dir, struct dentry *old_dentry,
 	loff_t pos;
 	int err;
 
+	if (new_dentry->d_inode && S_ISDIR(new_dentry->d_inode->i_mode))
+		dentry_unhash(new_dentry);
+
 	/* 1. locate source dd */
 	err = logfs_get_dd(old_dir, old_dentry, &dd, &pos);
 	if (err)