From: Valerie Aurora <vaurora@xxxxxxxxxx> Copy up a file when opened with write permissions. Does not copy up the file data when O_TRUNC is specified. Original-author: Valerie Aurora <vaurora@xxxxxxxxxx> Signed-off-by: David Howells <dhowells@xxxxxxxxxx> --- fs/namei.c | 31 +++++++++++++++++++++++++++++++ 1 files changed, 31 insertions(+), 0 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index dad7bef..4fe8f4c 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2521,6 +2521,24 @@ static inline int open_to_namei_flags(int flag) return flag; } +static int open_union_copyup(struct nameidata *nd, struct path *path, + int open_flag) +{ + struct vfsmount *oldmnt = path->mnt; + int error; + + if (open_flag & O_TRUNC) + error = union_copyup_len(nd, path, 0); + else + error = union_copyup(nd, path); + if (error) + return error; + if (oldmnt != path->mnt) + mntput(nd->path.mnt); + + return error; +} + /* * Handle the last step of open() */ @@ -2586,6 +2604,13 @@ static struct file *do_last(struct nameidata *nd, struct path *path, if (!nd->inode->i_op->lookup) goto exit; } + + if (acc_mode & MAY_WRITE) { + error = open_union_copyup(nd, &nd->path, open_flag); + if (error) + goto exit; + } + audit_inode(pathname, nd->path.dentry); goto ok; } @@ -2669,6 +2694,12 @@ static struct file *do_last(struct nameidata *nd, struct path *path, if (path->dentry->d_inode->i_op->follow_link) return NULL; + if (acc_mode & MAY_WRITE) { + error = open_union_copyup(nd, path, open_flag); + if (error) + goto exit_dput; + } + path_to_nameidata(path, nd); nd->inode = path->dentry->d_inode; /* Why this, you ask? _Now_ we might have grown LOOKUP_JUMPED... */ -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html