From: Melissa Howland Locking added so that multithreaded applications can now do writes from different threads without the risk of storage corruption. Signed-off-by: Melissa Howland Signed-off-by: Martin Schwidefsky --- drivers/s390/char/monwriter.c | 6 ++++++ 1 file changed, 6 insertions(+) Index: quilt-2.6/drivers/s390/char/monwriter.c =================================================================== --- quilt-2.6.orig/drivers/s390/char/monwriter.c +++ quilt-2.6/drivers/s390/char/monwriter.c @@ -17,6 +17,7 @@ #include #include #include +#include #include #include #include @@ -41,6 +42,7 @@ struct mon_private { size_t hdr_to_read; size_t data_to_read; struct mon_buf *current_buf; + struct mutex thread_mutex; }; /* @@ -179,6 +181,7 @@ static int monwrite_open(struct inode *i return -ENOMEM; INIT_LIST_HEAD(&monpriv->list); monpriv->hdr_to_read = sizeof(monpriv->hdr); + mutex_init(&monpriv->thread_mutex); filp->private_data = monpriv; return nonseekable_open(inode, filp); } @@ -209,6 +212,7 @@ static ssize_t monwrite_write(struct fil void *to; int rc; + mutex_lock(&monpriv->thread_mutex); for (written = 0; written < count; ) { if (monpriv->hdr_to_read) { len = min(count - written, monpriv->hdr_to_read); @@ -247,11 +251,13 @@ static ssize_t monwrite_write(struct fil } monpriv->hdr_to_read = sizeof(monpriv->hdr); } + mutex_unlock(&monpriv->thread_mutex); return written; out_error: monpriv->data_to_read = 0; monpriv->hdr_to_read = sizeof(struct monwrite_hdr); + mutex_unlock(&monpriv->thread_mutex); return rc; } -- blue skies, Martin. "Reality continues to ruin my life." - Calvin. - 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/