[PATCH] r/o bind mounts: unlink: monitor i_nlink

When a filesystem decrements i_nlink to zero, it means that a write must be
performed in order to drop the inode from the filesystem.

We're shortly going to have keep filesystems from being remounted r/o between
the time that this i_nlink decrement and that write occurs.

So, add a little helper function to do the decrements.  We'll tie into it in a
bit to note when i_nlink hits zero.

Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/usb/core/inode.c

@@ -332,7 +332,7 @@ static int usbfs_unlink (struct inode *dir, struct dentry *dentry)
 {
 	struct inode *inode = dentry->d_inode;
 	mutex_lock(&inode->i_mutex);
-	dentry->d_inode->i_nlink--;
+	drop_nlink(dentry->d_inode);
 	dput(dentry);
 	mutex_unlock(&inode->i_mutex);
 	d_delete(dentry);
@@ -347,10 +347,11 @@ static int usbfs_rmdir(struct inode *dir, struct dentry *dentry)
 	mutex_lock(&inode->i_mutex);
 	dentry_unhash(dentry);
 	if (usbfs_empty(dentry)) {
-		dentry->d_inode->i_nlink -= 2;
+		drop_nlink(dentry->d_inode);
+		drop_nlink(dentry->d_inode);
 		dput(dentry);
 		inode->i_flags |= S_DEAD;
-		dir->i_nlink--;
+		drop_nlink(dir);
 		error = 0;
 	}
 	mutex_unlock(&inode->i_mutex);

fs/autofs/root.c

@@ -414,7 +414,7 @@ static int autofs_root_rmdir(struct inode *dir, struct dentry *dentry)
 
 	dentry->d_time = (unsigned long)(struct autofs_dir_ent *)NULL;
 	autofs_hash_delete(ent);
-	dir->i_nlink--;
+	drop_nlink(dir);
 	d_drop(dentry);
 	unlock_kernel();
 

fs/autofs4/root.c

@@ -676,7 +676,7 @@ static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry)
 	dentry->d_inode->i_nlink = 0;
 
 	if (dir->i_nlink)
-		dir->i_nlink--;
+		drop_nlink(dir);
 
 	return 0;
 }

fs/bfs/dir.c

@@ -117,8 +117,7 @@ static int bfs_create(struct inode * dir, struct dentry * dentry, int mode,
 
 	err = bfs_add_entry(dir, dentry->d_name.name, dentry->d_name.len, inode->i_ino);
 	if (err) {
-		inode->i_nlink--;
-		mark_inode_dirty(inode);
+		inode_dec_link_count(inode);
 		iput(inode);
 		unlock_kernel();
 		return err;
@@ -196,9 +195,8 @@ static int bfs_unlink(struct inode * dir, struct dentry * dentry)
 	mark_buffer_dirty(bh);
 	dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC;
 	mark_inode_dirty(dir);
-	inode->i_nlink--;
 	inode->i_ctime = dir->i_ctime;
-	mark_inode_dirty(inode);
+	inode_dec_link_count(inode);
 	error = 0;
 
 out_brelse:
@@ -249,9 +247,8 @@ static int bfs_rename(struct inode * old_dir, struct dentry * old_dentry,
 	old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME_SEC;
 	mark_inode_dirty(old_dir);
 	if (new_inode) {
-		new_inode->i_nlink--;
 		new_inode->i_ctime = CURRENT_TIME_SEC;
-		mark_inode_dirty(new_inode);
+		inode_dec_link_count(new_inode);
 	}
 	mark_buffer_dirty(old_bh);
 	error = 0;

fs/cifs/inode.c

@@ -590,7 +590,7 @@ int cifs_unlink(struct inode *inode, struct dentry *direntry)
 
 	if (!rc) {
 		if (direntry->d_inode)
-			direntry->d_inode->i_nlink--;
+			drop_nlink(direntry->d_inode);
 	} else if (rc == -ENOENT) {
 		d_drop(direntry);
 	} else if (rc == -ETXTBSY) {
@@ -609,7 +609,7 @@ int cifs_unlink(struct inode *inode, struct dentry *direntry)
 						CIFS_MOUNT_MAP_SPECIAL_CHR);
 			CIFSSMBClose(xid, pTcon, netfid);
 			if (direntry->d_inode)
-				direntry->d_inode->i_nlink--;
+				drop_nlink(direntry->d_inode);
 		}
 	} else if (rc == -EACCES) {
 		/* try only if r/o attribute set in local lookup data? */
@@ -663,7 +663,7 @@ int cifs_unlink(struct inode *inode, struct dentry *direntry)
 						CIFS_MOUNT_MAP_SPECIAL_CHR);
 			if (!rc) {
 				if (direntry->d_inode)
-					direntry->d_inode->i_nlink--;
+					drop_nlink(direntry->d_inode);
 			} else if (rc == -ETXTBSY) {
 				int oplock = FALSE;
 				__u16 netfid;
@@ -684,7 +684,7 @@ int cifs_unlink(struct inode *inode, struct dentry *direntry)
 						    CIFS_MOUNT_MAP_SPECIAL_CHR);
 					CIFSSMBClose(xid, pTcon, netfid);
 					if (direntry->d_inode)
-			                        direntry->d_inode->i_nlink--;
+						drop_nlink(direntry->d_inode);
 				}
 			/* BB if rc = -ETXTBUSY goto the rename logic BB */
 			}
@@ -816,7 +816,7 @@ int cifs_rmdir(struct inode *inode, struct dentry *direntry)
 			  cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
 
 	if (!rc) {
-		inode->i_nlink--;
+		drop_nlink(inode);
 		i_size_write(direntry->d_inode,0);
 		direntry->d_inode->i_nlink = 0;
 	}

fs/coda/dir.c

@@ -367,7 +367,7 @@ int coda_unlink(struct inode *dir, struct dentry *de)
         }
 
 	coda_dir_changed(dir, 0);
-	de->d_inode->i_nlink--;
+	drop_nlink(de->d_inode);
 	unlock_kernel();
 
         return 0;
@@ -394,7 +394,7 @@ int coda_rmdir(struct inode *dir, struct dentry *de)
         }
 
 	coda_dir_changed(dir, -1);
-	de->d_inode->i_nlink--;
+	drop_nlink(de->d_inode);
 	d_delete(de);
 	unlock_kernel();
 

fs/ext2/namei.c

@@ -326,7 +326,7 @@ static int ext2_rename (struct inode * old_dir, struct dentry * old_dentry,
 		ext2_set_link(new_dir, new_de, new_page, old_inode);
 		new_inode->i_ctime = CURRENT_TIME_SEC;
 		if (dir_de)
-			new_inode->i_nlink--;
+			drop_nlink(new_inode);
 		inode_dec_link_count(new_inode);
 	} else {
 		if (dir_de) {

fs/ext3/namei.c

@@ -1621,7 +1621,7 @@ static inline void ext3_inc_count(handle_t *handle, struct inode *inode)
 
 static inline void ext3_dec_count(handle_t *handle, struct inode *inode)
 {
-	inode->i_nlink--;
+	drop_nlink(inode);
 }
 
 static int ext3_add_nondir(handle_t *handle,
@@ -1743,7 +1743,7 @@ retry:
 	inode->i_size = EXT3_I(inode)->i_disksize = inode->i_sb->s_blocksize;
 	dir_block = ext3_bread (handle, inode, 0, 1, &err);
 	if (!dir_block) {
-		inode->i_nlink--; /* is this nlink == 0? */
+		drop_nlink(inode); /* is this nlink == 0? */
 		ext3_mark_inode_dirty(handle, inode);
 		iput (inode);
 		goto out_stop;
@@ -2053,7 +2053,7 @@ static int ext3_rmdir (struct inode * dir, struct dentry *dentry)
 	ext3_orphan_add(handle, inode);
 	inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC;
 	ext3_mark_inode_dirty(handle, inode);
-	dir->i_nlink--;
+	drop_nlink(dir);
 	ext3_update_dx_flag(dir);
 	ext3_mark_inode_dirty(handle, dir);
 
@@ -2104,7 +2104,7 @@ static int ext3_unlink(struct inode * dir, struct dentry *dentry)
 	dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC;
 	ext3_update_dx_flag(dir);
 	ext3_mark_inode_dirty(handle, dir);
-	inode->i_nlink--;
+	drop_nlink(inode);
 	if (!inode->i_nlink)
 		ext3_orphan_add(handle, inode);
 	inode->i_ctime = dir->i_ctime;
@@ -2326,7 +2326,7 @@ static int ext3_rename (struct inode * old_dir, struct dentry *old_dentry,
 	}
 
 	if (new_inode) {
-		new_inode->i_nlink--;
+		drop_nlink(new_inode);
 		new_inode->i_ctime = CURRENT_TIME_SEC;
 	}
 	old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME_SEC;
@@ -2337,9 +2337,9 @@ static int ext3_rename (struct inode * old_dir, struct dentry *old_dentry,
 		PARENT_INO(dir_bh->b_data) = cpu_to_le32(new_dir->i_ino);
 		BUFFER_TRACE(dir_bh, "call ext3_journal_dirty_metadata");
 		ext3_journal_dirty_metadata(handle, dir_bh);
-		old_dir->i_nlink--;
+		drop_nlink(old_dir);
 		if (new_inode) {
-			new_inode->i_nlink--;
+			drop_nlink(new_inode);
 		} else {
 			new_dir->i_nlink++;
 			ext3_update_dx_flag(new_dir);

fs/hfs/dir.c

@@ -246,7 +246,7 @@ static int hfs_unlink(struct inode *dir, struct dentry *dentry)
 	if (res)
 		return res;
 
-	inode->i_nlink--;
+	drop_nlink(inode);
 	hfs_delete_inode(inode);
 	inode->i_ctime = CURRENT_TIME_SEC;
 	mark_inode_dirty(inode);

fs/hfsplus/dir.c

@@ -338,7 +338,7 @@ static int hfsplus_unlink(struct inode *dir, struct dentry *dentry)
 		return res;
 
 	if (inode->i_nlink > 0)
-		inode->i_nlink--;
+		drop_nlink(inode);
 	hfsplus_delete_inode(inode);
 	if (inode->i_ino != cnid && !inode->i_nlink) {
 		if (!atomic_read(&HFSPLUS_I(inode).opencnt)) {

fs/hpfs/namei.c

@@ -434,7 +434,7 @@ again:
 		unlock_kernel();
 		return -ENOSPC;
 	default:
-		inode->i_nlink--;
+		drop_nlink(inode);
 		err = 0;
 	}
 	goto out;
@@ -494,7 +494,7 @@ static int hpfs_rmdir(struct inode *dir, struct dentry *dentry)
 		err = -ENOSPC;
 		break;
 	default:
-		dir->i_nlink--;
+		drop_nlink(dir);
 		inode->i_nlink = 0;
 		err = 0;
 	}
@@ -636,7 +636,7 @@ static int hpfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	hpfs_i(i)->i_parent_dir = new_dir->i_ino;
 	if (S_ISDIR(i->i_mode)) {
 		new_dir->i_nlink++;
-		old_dir->i_nlink--;
+		drop_nlink(old_dir);
 	}
 	if ((fnode = hpfs_map_fnode(i->i_sb, i->i_ino, &bh))) {
 		fnode->up = new_dir->i_ino;

fs/jffs/inode-v23.c

@@ -1052,9 +1052,8 @@ jffs_remove(struct inode *dir, struct dentry *dentry, int type)
 
 	dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC;
 	mark_inode_dirty(dir);
-	inode->i_nlink--;
 	inode->i_ctime = dir->i_ctime;
-	mark_inode_dirty(inode);
+	inode_dec_link_count(inode);
 
 	d_delete(dentry);	/* This also frees the inode */
 

fs/jffs2/dir.c

@@ -615,7 +615,7 @@ static int jffs2_rmdir (struct inode *dir_i, struct dentry *dentry)
 	}
 	ret = jffs2_unlink(dir_i, dentry);
 	if (!ret)
-		dir_i->i_nlink--;
+		drop_nlink(dir_i);
 	return ret;
 }
 
@@ -823,7 +823,7 @@ static int jffs2_rename (struct inode *old_dir_i, struct dentry *old_dentry,
 
 	if (victim_f) {
 		/* There was a victim. Kill it off nicely */
-		new_dentry->d_inode->i_nlink--;
+		drop_nlink(new_dentry->d_inode);
 		/* Don't oops if the victim was a dirent pointing to an
 		   inode which didn't exist. */
 		if (victim_f->inocache) {
@@ -862,7 +862,7 @@ static int jffs2_rename (struct inode *old_dir_i, struct dentry *old_dentry,
 	}
 
 	if (S_ISDIR(old_dentry->d_inode->i_mode))
-		old_dir_i->i_nlink--;
+		drop_nlink(old_dir_i);
 
 	new_dir_i->i_mtime = new_dir_i->i_ctime = old_dir_i->i_mtime = old_dir_i->i_ctime = ITIME(now);
 

fs/jfs/namei.c

@@ -393,9 +393,8 @@ static int jfs_rmdir(struct inode *dip, struct dentry *dentry)
 	/* update parent directory's link count corresponding
 	 * to ".." entry of the target directory deleted
 	 */
-	dip->i_nlink--;
 	dip->i_ctime = dip->i_mtime = CURRENT_TIME;
-	mark_inode_dirty(dip);
+	inode_dec_link_count(dip);
 
 	/*
 	 * OS/2 could have created EA and/or ACL
@@ -515,8 +514,7 @@ static int jfs_unlink(struct inode *dip, struct dentry *dentry)
 	mark_inode_dirty(dip);
 
 	/* update target's inode */
-	ip->i_nlink--;
-	mark_inode_dirty(ip);
+	inode_dec_link_count(ip);
 
 	/*
 	 *      commit zero link count object
@@ -835,7 +833,7 @@ static int jfs_link(struct dentry *old_dentry,
 	rc = txCommit(tid, 2, &iplist[0], 0);
 
 	if (rc) {
-		ip->i_nlink--;
+		ip->i_nlink--; /* never instantiated */
 		iput(ip);
 	} else
 		d_instantiate(dentry, ip);
@@ -1155,9 +1153,9 @@ static int jfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 			      old_ip->i_ino, JFS_RENAME);
 		if (rc)
 			goto out4;
-		new_ip->i_nlink--;
+		drop_nlink(new_ip);
 		if (S_ISDIR(new_ip->i_mode)) {
-			new_ip->i_nlink--;
+			drop_nlink(new_ip);
 			if (new_ip->i_nlink) {
 				mutex_unlock(&JFS_IP(new_ip)->commit_mutex);
 				if (old_dir != new_dir)
@@ -1223,7 +1221,7 @@ static int jfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 		goto out4;
 	}
 	if (S_ISDIR(old_ip->i_mode)) {
-		old_dir->i_nlink--;
+		drop_nlink(old_dir);
 		if (old_dir != new_dir) {
 			/*
 			 * Change inode number of parent for moved directory

fs/libfs.c

@@ -275,7 +275,7 @@ int simple_unlink(struct inode *dir, struct dentry *dentry)
 	struct inode *inode = dentry->d_inode;
 
 	inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
-	inode->i_nlink--;
+	drop_nlink(inode);
 	dput(dentry);
 	return 0;
 }
@@ -285,9 +285,9 @@ int simple_rmdir(struct inode *dir, struct dentry *dentry)
 	if (!simple_empty(dentry))
 		return -ENOTEMPTY;
 
-	dentry->d_inode->i_nlink--;
+	drop_nlink(dentry->d_inode);
 	simple_unlink(dir, dentry);
-	dir->i_nlink--;
+	drop_nlink(dir);
 	return 0;
 }
 
@@ -303,9 +303,9 @@ int simple_rename(struct inode *old_dir, struct dentry *old_dentry,
 	if (new_dentry->d_inode) {
 		simple_unlink(new_dir, new_dentry);
 		if (they_are_dirs)
-			old_dir->i_nlink--;
+			drop_nlink(old_dir);
 	} else if (they_are_dirs) {
-		old_dir->i_nlink--;
+		drop_nlink(old_dir);
 		new_dir->i_nlink++;
 	}
 

fs/minix/namei.c

@@ -249,7 +249,7 @@ static int minix_rename(struct inode * old_dir, struct dentry *old_dentry,
 		minix_set_link(new_de, new_page, old_inode);
 		new_inode->i_ctime = CURRENT_TIME_SEC;
 		if (dir_de)
-			new_inode->i_nlink--;
+			drop_nlink(new_inode);
 		inode_dec_link_count(new_inode);
 	} else {
 		if (dir_de) {

fs/msdos/namei.c

@@ -343,7 +343,7 @@ static int msdos_rmdir(struct inode *dir, struct dentry *dentry)
 	err = fat_remove_entries(dir, &sinfo);	/* and releases bh */
 	if (err)
 		goto out;
-	dir->i_nlink--;
+	drop_nlink(dir);
 
 	inode->i_nlink = 0;
 	inode->i_ctime = CURRENT_TIME_SEC;
@@ -549,7 +549,7 @@ static int do_msdos_rename(struct inode *old_dir, unsigned char *old_name,
 			if (err)
 				goto error_dotdot;
 		}
-		old_dir->i_nlink--;
+		drop_nlink(old_dir);
 		if (!new_inode)
 			new_dir->i_nlink++;
 	}
@@ -566,10 +566,9 @@ static int do_msdos_rename(struct inode *old_dir, unsigned char *old_name,
 		mark_inode_dirty(old_dir);
 
 	if (new_inode) {
+		drop_nlink(new_inode);
 		if (is_dir)
-			new_inode->i_nlink -= 2;
-		else
-			new_inode->i_nlink--;
+			drop_nlink(new_inode);
 		new_inode->i_ctime = ts;
 	}
 out:

fs/nfs/dir.c

@@ -843,7 +843,7 @@ static void nfs_dentry_iput(struct dentry *dentry, struct inode *inode)
 	nfs_inode_return_delegation(inode);
 	if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
 		lock_kernel();
-		inode->i_nlink--;
+		drop_nlink(inode);
 		nfs_complete_unlink(dentry);
 		unlock_kernel();
 	}
@@ -1401,7 +1401,7 @@ static int nfs_safe_remove(struct dentry *dentry)
 		error = NFS_PROTO(dir)->remove(dir, &dentry->d_name);
 		/* The VFS may want to delete this inode */
 		if (error == 0)
-			inode->i_nlink--;
+			drop_nlink(inode);
 		nfs_mark_for_revalidate(inode);
 		nfs_end_data_update(inode);
 	} else
@@ -1639,7 +1639,7 @@ static int nfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 			goto out;
 		}
 	} else
-		new_inode->i_nlink--;
+		drop_nlink(new_inode);
 
 go_ahead:
 	/*

fs/ocfs2/namei.c

@@ -739,7 +739,7 @@ static int ocfs2_link(struct dentry *old_dentry,
 	err = ocfs2_journal_dirty(handle, fe_bh);
 	if (err < 0) {
 		le16_add_cpu(&fe->i_links_count, -1);
-		inode->i_nlink--;
+		drop_nlink(inode);
 		mlog_errno(err);
 		goto bail;
 	}
@@ -749,7 +749,7 @@ static int ocfs2_link(struct dentry *old_dentry,
 			      parent_fe_bh, de_bh);
 	if (err) {
 		le16_add_cpu(&fe->i_links_count, -1);
-		inode->i_nlink--;
+		drop_nlink(inode);
 		mlog_errno(err);
 		goto bail;
 	}

fs/qnx4/namei.c

@@ -189,8 +189,7 @@ int qnx4_rmdir(struct inode *dir, struct dentry *dentry)
 	inode->i_nlink = 0;
 	mark_inode_dirty(inode);
 	inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC;
-	dir->i_nlink--;
-	mark_inode_dirty(dir);
+	inode_dec_link_count(dir);
 	retval = 0;
 
       end_rmdir:
@@ -234,9 +233,8 @@ int qnx4_unlink(struct inode *dir, struct dentry *dentry)
 	mark_buffer_dirty(bh);
 	dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC;
 	mark_inode_dirty(dir);
-	inode->i_nlink--;
 	inode->i_ctime = dir->i_ctime;
-	mark_inode_dirty(inode);
+	inode_dec_link_count(inode);
 	retval = 0;
 
 end_unlink:

fs/reiserfs/namei.c

@@ -20,7 +20,7 @@
 #include <linux/quotaops.h>
 
 #define INC_DIR_INODE_NLINK(i) if (i->i_nlink != 1) { i->i_nlink++; if (i->i_nlink >= REISERFS_LINK_MAX) i->i_nlink=1; }
-#define DEC_DIR_INODE_NLINK(i) if (i->i_nlink != 1) i->i_nlink--;
+#define DEC_DIR_INODE_NLINK(i) if (i->i_nlink != 1) drop_nlink(i);
 
 // directory item contains array of entry headers. This performs
 // binary search through that array
@@ -994,7 +994,7 @@ static int reiserfs_unlink(struct inode *dir, struct dentry *dentry)
 		inode->i_nlink = 1;
 	}
 
-	inode->i_nlink--;
+	drop_nlink(inode);
 
 	/*
 	 * we schedule before doing the add_save_link call, save the link
@@ -1475,7 +1475,7 @@ static int reiserfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 		if (S_ISDIR(new_dentry_inode->i_mode)) {
 			new_dentry_inode->i_nlink = 0;
 		} else {
-			new_dentry_inode->i_nlink--;
+			drop_nlink(new_dentry_inode);
 		}
 		new_dentry_inode->i_ctime = ctime;
 		savelink = new_dentry_inode->i_nlink;

fs/sysv/namei.c

@@ -250,7 +250,7 @@ static int sysv_rename(struct inode * old_dir, struct dentry * old_dentry,
 		sysv_set_link(new_de, new_page, old_inode);
 		new_inode->i_ctime = CURRENT_TIME_SEC;
 		if (dir_de)
-			new_inode->i_nlink--;
+			drop_nlink(new_inode);
 		inode_dec_link_count(new_inode);
 	} else {
 		if (dir_de) {

fs/udf/namei.c

@@ -878,8 +878,7 @@ static int udf_rmdir(struct inode * dir, struct dentry * dentry)
 			inode->i_nlink);
 	inode->i_nlink = 0;
 	inode->i_size = 0;
-	mark_inode_dirty(inode);
-	dir->i_nlink --;
+	inode_dec_link_count(inode);
 	inode->i_ctime = dir->i_ctime = dir->i_mtime = current_fs_time(dir->i_sb);
 	mark_inode_dirty(dir);
 
@@ -923,8 +922,7 @@ static int udf_unlink(struct inode * dir, struct dentry * dentry)
 		goto end_unlink;
 	dir->i_ctime = dir->i_mtime = current_fs_time(dir->i_sb);
 	mark_inode_dirty(dir);
-	inode->i_nlink--;
-	mark_inode_dirty(inode);
+	inode_dec_link_count(inode);
 	inode->i_ctime = dir->i_ctime;
 	retval = 0;
 
@@ -1101,8 +1099,7 @@ out:
 	return err;
 
 out_no_entry:
-	inode->i_nlink--;
-	mark_inode_dirty(inode);
+	inode_dec_link_count(inode);
 	iput(inode);
 	goto out;
 }
@@ -1261,9 +1258,8 @@ static int udf_rename (struct inode * old_dir, struct dentry * old_dentry,
 
 	if (new_inode)
 	{
-		new_inode->i_nlink--;
 		new_inode->i_ctime = current_fs_time(new_inode->i_sb);
-		mark_inode_dirty(new_inode);
+		inode_dec_link_count(new_inode);
 	}
 	old_dir->i_ctime = old_dir->i_mtime = current_fs_time(old_dir->i_sb);
 	mark_inode_dirty(old_dir);
@@ -1279,12 +1275,10 @@ static int udf_rename (struct inode * old_dir, struct dentry * old_dentry,
 		}
 		else
 			mark_buffer_dirty_inode(dir_bh, old_inode);
-		old_dir->i_nlink --;
-		mark_inode_dirty(old_dir);
+		inode_dec_link_count(old_dir);
 		if (new_inode)
 		{
-			new_inode->i_nlink --;
-			mark_inode_dirty(new_inode);
+			inode_dec_link_count(new_inode);
 		}
 		else
 		{

fs/ufs/namei.c

@@ -308,7 +308,7 @@ static int ufs_rename(struct inode *old_dir, struct dentry *old_dentry,
 		ufs_set_link(new_dir, new_de, new_page, old_inode);
 		new_inode->i_ctime = CURRENT_TIME_SEC;
 		if (dir_de)
-			new_inode->i_nlink--;
+			drop_nlink(new_inode);
 		inode_dec_link_count(new_inode);
 	} else {
 		if (dir_de) {

fs/vfat/namei.c

@@ -782,7 +782,7 @@ static int vfat_rmdir(struct inode *dir, struct dentry *dentry)
 	err = fat_remove_entries(dir, &sinfo);	/* and releases bh */
 	if (err)
 		goto out;
-	dir->i_nlink--;
+	drop_nlink(dir);
 
 	inode->i_nlink = 0;
 	inode->i_mtime = inode->i_atime = CURRENT_TIME_SEC;
@@ -930,7 +930,7 @@ static int vfat_rename(struct inode *old_dir, struct dentry *old_dentry,
 			if (err)
 				goto error_dotdot;
 		}
-		old_dir->i_nlink--;
+		drop_nlink(old_dir);
 		if (!new_inode)
  			new_dir->i_nlink++;
 	}
@@ -947,10 +947,9 @@ static int vfat_rename(struct inode *old_dir, struct dentry *old_dentry,
 		mark_inode_dirty(old_dir);
 
 	if (new_inode) {
+		drop_nlink(new_inode);
 		if (is_dir)
-			new_inode->i_nlink -= 2;
-		else
-			new_inode->i_nlink--;
+			drop_nlink(new_inode);
 		new_inode->i_ctime = ts;
 	}
 out:

include/linux/fs.h

@@ -1225,9 +1225,14 @@ static inline void inode_inc_link_count(struct inode *inode)
 	mark_inode_dirty(inode);
 }
 
-static inline void inode_dec_link_count(struct inode *inode)
+static inline void drop_nlink(struct inode *inode)
 {
 	inode->i_nlink--;
+}
+
+static inline void inode_dec_link_count(struct inode *inode)
+{
+	drop_nlink(inode);
 	mark_inode_dirty(inode);
 }
 

ipc/mqueue.c

@@ -307,7 +307,7 @@ static int mqueue_unlink(struct inode *dir, struct dentry *dentry)
 
 	dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME;
 	dir->i_size -= DIRENT_SIZE;
-  	inode->i_nlink--;
+  	drop_nlink(inode);
   	dput(dentry);
   	return 0;
 }

mm/shmem.c

@@ -1772,7 +1772,7 @@ static int shmem_unlink(struct inode *dir, struct dentry *dentry)
 
 	dir->i_size -= BOGO_DIRENT_SIZE;
 	inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
-	inode->i_nlink--;
+	drop_nlink(inode);
 	dput(dentry);	/* Undo the count from "create" - this does all the work */
 	return 0;
 }
@@ -1782,8 +1782,8 @@ static int shmem_rmdir(struct inode *dir, struct dentry *dentry)
 	if (!simple_empty(dentry))
 		return -ENOTEMPTY;
 
-	dentry->d_inode->i_nlink--;
-	dir->i_nlink--;
+	drop_nlink(dentry->d_inode);
+	drop_nlink(dir);
 	return shmem_unlink(dir, dentry);
 }
 
@@ -1804,9 +1804,9 @@ static int shmem_rename(struct inode *old_dir, struct dentry *old_dentry, struct
 	if (new_dentry->d_inode) {
 		(void) shmem_unlink(new_dir, new_dentry);
 		if (they_are_dirs)
-			old_dir->i_nlink--;
+			drop_nlink(old_dir);
 	} else if (they_are_dirs) {
-		old_dir->i_nlink--;
+		drop_nlink(old_dir);
 		new_dir->i_nlink++;
 	}