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Commit b7ca6928 authored by Steve French's avatar Steve French
Browse files

CIFS: Protect i_nlink from being negative 



that can cause warning messages.  Pavel had initially
suggested a smaller patch around drop_nlink, after
a similar problem was discovered NFS.  Protecting
additional places where nlink is touched was
suggested by Jeff Layton and is included in this.

Reviewed-by: default avatarPavel Shilovsky <pshilovsky@samba.org>
Reviewed-by: default avatarJeff Layton <jlayton@redhat.com>
Signed-off-by: default avatarSteve French <sfrench@us.ibm.com>
Signed-off-by: default avatarSteve French <smfrench@gmail.com>
parent 6dab7ede

fs/cifs/inode.c

+16 −8
Original line number Diff line number Diff line
@@ -124,10 +124,10 @@ cifs_fattr_to_inode(struct inode *inode, struct cifs_fattr *fattr) 
{

	struct cifsInodeInfo *cifs_i = CIFS_I(inode);

	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);

	unsigned long oldtime = cifs_i->time;



	cifs_revalidate_cache(inode, fattr);



	spin_lock(&inode->i_lock);

	inode->i_atime = fattr->cf_atime;

	inode->i_mtime = fattr->cf_mtime;

	inode->i_ctime = fattr->cf_ctime;
@@ -148,9 +148,6 @@ cifs_fattr_to_inode(struct inode *inode, struct cifs_fattr *fattr) 
	else

		cifs_i->time = jiffies;



	cFYI(1, "inode 0x%p old_time=%ld new_time=%ld", inode,

		 oldtime, cifs_i->time);



	cifs_i->delete_pending = fattr->cf_flags & CIFS_FATTR_DELETE_PENDING;



	cifs_i->server_eof = fattr->cf_eof;
@@ -158,7 +155,6 @@ cifs_fattr_to_inode(struct inode *inode, struct cifs_fattr *fattr) 
	 * Can't safely change the file size here if the client is writing to

	 * it due to potential races.

	 */

	spin_lock(&inode->i_lock);

	if (is_size_safe_to_change(cifs_i, fattr->cf_eof)) {

		i_size_write(inode, fattr->cf_eof);
@@ -859,12 +855,14 @@ struct inode *cifs_root_iget(struct super_block *sb) 


	if (rc && tcon->ipc) {

		cFYI(1, "ipc connection - fake read inode");

		spin_lock(&inode->i_lock);

		inode->i_mode |= S_IFDIR;

		set_nlink(inode, 2);

		inode->i_op = &cifs_ipc_inode_ops;

		inode->i_fop = &simple_dir_operations;

		inode->i_uid = cifs_sb->mnt_uid;

		inode->i_gid = cifs_sb->mnt_gid;

		spin_unlock(&inode->i_lock);

	} else if (rc) {

		iget_failed(inode);

		inode = ERR_PTR(rc);
@@ -1110,6 +1108,15 @@ undo_setattr: 
	goto out_close;

}



/* copied from fs/nfs/dir.c with small changes */

static void

cifs_drop_nlink(struct inode *inode)

{

	spin_lock(&inode->i_lock);

	if (inode->i_nlink > 0)

		drop_nlink(inode);

	spin_unlock(&inode->i_lock);

}



/*

 * If dentry->d_inode is null (usually meaning the cached dentry
@@ -1166,13 +1173,13 @@ retry_std_delete: 
psx_del_no_retry:

	if (!rc) {

		if (inode)

			drop_nlink(inode);

			cifs_drop_nlink(inode);

	} else if (rc == -ENOENT) {

		d_drop(dentry);

	} else if (rc == -ETXTBSY) {

		rc = cifs_rename_pending_delete(full_path, dentry, xid);

		if (rc == 0)

			drop_nlink(inode);

			cifs_drop_nlink(inode);

	} else if ((rc == -EACCES) && (dosattr == 0) && inode) {

		attrs = kzalloc(sizeof(*attrs), GFP_KERNEL);

		if (attrs == NULL) {
@@ -1241,9 +1248,10 @@ cifs_mkdir_qinfo(struct inode *inode, struct dentry *dentry, umode_t mode, 
	 * setting nlink not necessary except in cases where we failed to get it

	 * from the server or was set bogus

	 */

	spin_lock(&dentry->d_inode->i_lock);

	if ((dentry->d_inode) && (dentry->d_inode->i_nlink < 2))

		set_nlink(dentry->d_inode, 2);



	spin_unlock(&dentry->d_inode->i_lock);

	mode &= ~current_umask();

	/* must turn on setgid bit if parent dir has it */

	if (inode->i_mode & S_ISGID)

fs/cifs/link.c

+2 −0
Original line number Diff line number Diff line
@@ -433,7 +433,9 @@ cifs_hardlink(struct dentry *old_file, struct inode *inode, 
	if (old_file->d_inode) {

		cifsInode = CIFS_I(old_file->d_inode);

		if (rc == 0) {

			spin_lock(&old_file->d_inode->i_lock);

			inc_nlink(old_file->d_inode);

			spin_unlock(&old_file->d_inode->i_lock);

/* BB should we make this contingent on superblock flag NOATIME? */

/*			old_file->d_inode->i_ctime = CURRENT_TIME;*/

			/* parent dir timestamps will update from srv