lkml.org 
[lkml]   [2010]   [Jun]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 31/38] union-mount: Implement union-aware writable open()
    Date
    Copy up a file when opened with write permissions.  Does not copy up
    the file data when O_TRUNC is specified.
    ---
    fs/namei.c | 28 ++++++++++++++++++++++++++++
    1 files changed, 28 insertions(+), 0 deletions(-)

    diff --git a/fs/namei.c b/fs/namei.c
    index 6096413..7514096 100644
    --- a/fs/namei.c
    +++ b/fs/namei.c
    @@ -1907,6 +1907,24 @@ exit:
    return ERR_PTR(error);
    }

    +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;
    +}
    +
    static struct file *do_last(struct nameidata *nd, struct path *path,
    int open_flag, int acc_mode,
    int mode, const char *pathname)
    @@ -1958,6 +1976,11 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
    if (!path->dentry->d_inode->i_op->lookup)
    goto exit_dput;
    }
    + if (acc_mode & MAY_WRITE) {
    + error = open_union_copyup(nd, path, open_flag);
    + if (error)
    + goto exit_dput;
    + }
    path_to_nameidata(path, nd);
    audit_inode(pathname, nd->path.dentry);
    goto ok;
    @@ -2029,6 +2052,11 @@ 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);
    error = -EISDIR;
    if (S_ISDIR(path->dentry->d_inode->i_mode))
    --
    1.6.3.3


    \
     
     \ /
      Last update: 2010-06-15 20:45    [W:4.263 / U:0.408 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site