[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 <[email protected]> Acked-by: Christoph Hellwig <[email protected]> Cc: Al Viro <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
kyagi · Oct 1, 2006 · 9a53c3a · 9a53c3a
1 parent aab520e
commit 9a53c3a
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Showing 28 changed files with 83 additions and 93 deletions.
diff --git a/drivers/usb/core/inode.c b/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);

diff --git a/fs/autofs/root.c b/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();
 

diff --git a/fs/autofs4/root.c b/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;
 }

diff --git a/fs/bfs/dir.c b/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;

diff --git a/fs/cifs/inode.c b/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;
 	}

diff --git a/fs/coda/dir.c b/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();
 

diff --git a/fs/ext2/namei.c b/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) {

diff --git a/fs/ext3/namei.c b/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 @@ static int ext3_mkdir(struct inode * dir, struct dentry * dentry, int mode)
 	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);

diff --git a/fs/hfs/dir.c b/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);

diff --git a/fs/hfsplus/dir.c b/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)) {

diff --git a/fs/hpfs/namei.c b/fs/hpfs/namei.c
@@ -434,7 +434,7 @@ static int hpfs_unlink(struct inode *dir, struct dentry *dentry)
 		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;

diff --git a/fs/jffs/inode-v23.c b/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 */
 

diff --git a/fs/jffs2/dir.c b/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);
 

diff --git a/fs/jfs/namei.c b/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

diff --git a/fs/libfs.c b/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++;
 	}
 

diff --git a/fs/minix/namei.c b/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) {