lkml.org 
[lkml]   [2006]   [Aug]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    SubjectRe: [PATCH] fix wrong error code on interrupted close syscalls
    Date
    From
    On Thursday, 10-Aug-2006 at 19:36 EDT, Ernie Petrides wrote:

    > [...]
    > The bottom line is that close() syscalls are not restartable, and
    > thus -ERESTARTSYS return values should be mapped to -EINTR. This
    > is consistent with the close(2) manual page. The fix is below.
    > [...]
    > --- linux-2.6.17/fs/open.c.orig
    > +++ linux-2.6.17/fs/open.c
    > @@ -1172,6 +1172,7 @@ asmlinkage long sys_close(unsigned int f
    > struct file * filp;
    > struct files_struct *files = current->files;
    > struct fdtable *fdt;
    > + int retval;
    >
    > spin_lock(&files->file_lock);
    > fdt = files_fdtable(files);
    > @@ -1184,7 +1185,10 @@ asmlinkage long sys_close(unsigned int f
    > FD_CLR(fd, fdt->close_on_exec);
    > __put_unused_fd(files, fd);
    > spin_unlock(&files->file_lock);
    > - return filp_close(filp, files);
    > + retval = filp_close(filp, files);
    > +
    > + /* can't restart close syscall because file table entry was cleared */
    > + return (retval == -ERESTARTSYS) ? -EINTR : retval;
    >
    > out_unlock:
    > spin_unlock(&files->file_lock);


    Hi, Andrew. Roland McGrath has pointed out to me that my original patch
    for this problem only handles the case of ERESTARTSYS, but doesn't treat
    the three other restart pseudo-error codes similarly.

    I don't see how any code currently in the 2.6.17 source tree could possibly
    result in any ERESTARTNOINTR, ERESTARTNOHAND, or ERESTART_RESTARTBLOCK
    errors being sent back through filp_close().

    But if you prefer the extra checks for completeness, feel free to add
    the incremental patch below (on top of my previous patch to check for
    ERESTARTSYS).

    Cheers. -ernie



    --- linux-2.6.17/fs/open.c.prev
    +++ linux-2.6.17/fs/open.c
    @@ -1188,7 +1188,13 @@ asmlinkage long sys_close(unsigned int f
    retval = filp_close(filp, files);

    /* can't restart close syscall because file table entry was cleared */
    - return (retval == -ERESTARTSYS) ? -EINTR : retval;
    + if (unlikely(retval == -ERESTARTSYS ||
    + retval == -ERESTARTNOINTR ||
    + retval == -ERESTARTNOHAND ||
    + retval == -ERESTART_RESTARTBLOCK))
    + retval = -EINTR;
    +
    + return retval;

    out_unlock:
    spin_unlock(&files->file_lock);
    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/
    \
     
     \ /
      Last update: 2006-08-17 02:53    [W:0.021 / U:31.920 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site