This problem and patch were discovered and written by Alan Tyson of HP, who asked that I post this. The problem is this:
When the CIFS client mounts a share that does not have Unix extensions, it will turn off the "w" bits in the file mode if it sees that ATTR_READONLY is set. It has no corresponding logic, however, to reenable write permissions if the ATTR_READONLY flag is later removed. This results in a situation where a file gets "stuck" as read-only. Steps to reproduce this bug are in the following samba.org BZ: https://bugzilla.samba.org/show_bug.cgi?id=4443 The patch below corrects this with the following logic: If unix extensions were not negotiated for the mount, and the server does not report ATTR_READONLY being set for the file then check the mode bits on the inode. If no write bits are set, then assume that ATTR_READONLY was previously set for this file but is not now, and set any write bits allowed by the mnt_file_mode. This logic seems reasonable, but I'm not certain that there aren't cases where it would fall down. Comments and/or ACK's appreciated... Signed-off-by: Jeff Layton <[EMAIL PROTECTED]> diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c index 86b9dbb..e75a844 100644 --- a/fs/cifs/inode.c +++ b/fs/cifs/inode.c @@ -494,6 +494,12 @@ int cifs_get_inode_info(struct inode **pinode, mode e.g. 555 */ if (cifsInfo->cifsAttrs & ATTR_READONLY) inode->i_mode &= ~(S_IWUGO); + else if ((inode->i_mode & S_IWUGO) == 0) + /* the ATTR_READONLY flag may have been */ + /* changed on server -- set any w bits */ + /* allowed by mnt_file_mode */ + inode->i_mode |= (S_IWUGO & + cifs_sb->mnt_file_mode); /* BB add code here - validate if device or weird share or device type? */ } diff --git a/fs/cifs/readdir.c b/fs/cifs/readdir.c index 44cfb52..2a374d5 100644 --- a/fs/cifs/readdir.c +++ b/fs/cifs/readdir.c @@ -219,6 +219,10 @@ static void fill_in_inode(struct inode *tmp_inode, int new_buf_type, tmp_inode->i_mode |= S_IFREG; if (attr & ATTR_READONLY) tmp_inode->i_mode &= ~(S_IWUGO); + else if ((tmp_inode->i_mode & S_IWUGO) == 0) + /* the ATTR_READONLY flag may have been changed on */ + /* server -- set any w bits allowed by mnt_file_mode */ + tmp_inode->i_mode |= (S_IWUGO & cifs_sb->mnt_file_mode); } /* could add code here - to validate if device or weird share type? */ /* can not fill in nlink here as in qpathinfo version and Unx search */ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
