On Sun, 20 May 2012 23:24:39 -0500
shirishpargaonkar@xxxxxxxxx wrote:
> From: Shirish Pargaonkar <shirishpargaonkar@xxxxxxxxx>
>
> While traversing the linked list of open file handles, if the identfied
> file handle is invalid, a reopen is attempted and if it fails, we
> resume traversing where we stopped and cifs can oops while accessing
> invalid next element, for list might have changed.
>
> So mark the invalid file handle and attempt reopen if no
> valid file handle is found in rest of the list.
> If reopen fails, move the invalid file handle to the end of the list
> and start traversing the list again from the begining.
> Repeat this four times before giving up and returning an error if
> file reopen keeps failing.
>
> Cc: <stable@xxxxxxxxxxxxxxx>
> Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@xxxxxxxxx>
>
> ---
> fs/cifs/cifsglob.h | 1 +
> fs/cifs/file.c | 55 +++++++++++++++++++++++++++++----------------------
> 2 files changed, 32 insertions(+), 24 deletions(-)
>
[...]
> +
> + if (inv_file) {
> + rc = cifs_reopen_file(inv_file, false);
> + if (!rc)
> + return inv_file;
> + else {
> + list_move_tail(&inv_file->flist,
> + &cifs_inode->openFileList);
You're modifying this list w/o holding the spinlock. You need to do
this while holding the spinlock.
> + cifsFileInfo_put(inv_file);
> + spin_lock(&cifs_file_list_lock);
> + ++refind;
> + goto refind_writable;
> + }
> + }
> +
> return NULL;
> }
>
--
Jeff Layton <jlayton@xxxxxxxxxx>
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