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Commit 9a53c3a7 authored by Dave Hansen's avatar Dave Hansen Committed by Linus Torvalds
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[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: default avatarDave Hansen <haveblue@us.ibm.com>
Acked-by: default avatarChristoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent aab520e2

drivers/usb/core/inode.c

+4 −3
Original line number Diff line number Diff line
@@ -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

+1 −1
Original line number Diff line number Diff line
@@ -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

+1 −1
Original line number Diff line number Diff line
@@ -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

+3 −6
Original line number Diff line number Diff line
@@ -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

+5 −5
Original line number Diff line number Diff line
@@ -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;

	}