lkml.org 
[lkml]   [2020]   [Mar]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 4.9 63/88] cifs: dont leak -EAGAIN for stat() during reconnect
    Date
    From: Ronnie Sahlberg <lsahlber@redhat.com>

    commit fc513fac56e1b626ae48a74d7551d9c35c50129e upstream.

    If from cifs_revalidate_dentry_attr() the SMB2/QUERY_INFO call fails with an
    error, such as STATUS_SESSION_EXPIRED, causing the session to be reconnected
    it is possible we will leak -EAGAIN back to the application even for
    system calls such as stat() where this is not a valid error.

    Fix this by re-trying the operation from within cifs_revalidate_dentry_attr()
    if cifs_get_inode_info*() returns -EAGAIN.

    This fixes stat() and possibly also other system calls that uses
    cifs_revalidate_dentry*().

    Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
    Signed-off-by: Steve French <stfrench@microsoft.com>
    Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
    Reviewed-by: Aurelien Aptel <aaptel@suse.com>
    CC: Stable <stable@vger.kernel.org>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    ---
    fs/cifs/inode.c | 6 +++++-
    1 file changed, 5 insertions(+), 1 deletion(-)

    --- a/fs/cifs/inode.c
    +++ b/fs/cifs/inode.c
    @@ -1990,6 +1990,7 @@ int cifs_revalidate_dentry_attr(struct d
    struct inode *inode = d_inode(dentry);
    struct super_block *sb = dentry->d_sb;
    char *full_path = NULL;
    + int count = 0;

    if (inode == NULL)
    return -ENOENT;
    @@ -2011,15 +2012,18 @@ int cifs_revalidate_dentry_attr(struct d
    full_path, inode, inode->i_count.counter,
    dentry, cifs_get_time(dentry), jiffies);

    +again:
    if (cifs_sb_master_tcon(CIFS_SB(sb))->unix_ext)
    rc = cifs_get_inode_info_unix(&inode, full_path, sb, xid);
    else
    rc = cifs_get_inode_info(&inode, full_path, NULL, sb,
    xid, NULL);
    -
    + if (rc == -EAGAIN && count++ < 10)
    + goto again;
    out:
    kfree(full_path);
    free_xid(xid);
    +
    return rc;
    }


    \
     
     \ /
      Last update: 2020-03-10 14:35    [W:4.637 / U:0.072 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site