From b7ca69289680cf631fb20b7d436467c4ec1153cd Mon Sep 17 00:00:00 2001 From: Steve French Date: Fri, 3 Aug 2012 08:43:01 -0500 Subject: [PATCH] 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: Pavel Shilovsky Reviewed-by: Jeff Layton Signed-off-by: Steve French Signed-off-by: Steve French --- fs/cifs/inode.c | 24 ++++++++++++++++-------- fs/cifs/link.c | 2 ++ 2 files changed, 18 insertions(+), 8 deletions(-) diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c index 7354877fa3bd..cb79c7edecb0 100644 --- a/fs/cifs/inode.c +++ b/fs/cifs/inode.c @@ -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) diff --git a/fs/cifs/link.c b/fs/cifs/link.c index 09e4b3ae4564..e6ce3b112875 100644 --- a/fs/cifs/link.c +++ b/fs/cifs/link.c @@ -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