Messages in this thread Patch in this message |  | | | Date | Wed, 1 Sep 2004 11:19:40 +0300 | | From | "Michael S. Tsirkin" <> | | Subject | Re: f_ops flag to speed up compatible ioctls in linux kernel |
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Quoting Lee Revell (rlrevell@joe-job.com) "Re: f_ops flag to speed up compatible ioctls in linux kernel": > By adding a new ioctl you are adding a new use of the BKL. It has been > suggested on dri-devel that this should be fixed. Is this even > possible? > > Lee
I dont know - can the lock be released before the call to filp->f_op->ioctl ?
I assume the reason its there is for legacy code - existing ioctls may be assuming the BKL is taken, but maybe there could be another flag in f_ops to let sys_ioctl release the lock before doing the call ...
Like this - would that be safe?
--- linux-2.6.8.1/fs/ioctl.c 2004-08-14 13:54:51.000000000 +0300 +++ linux-2.6.8.1-built/fs/ioctl.c 2004-09-01 11:14:59.944417160 +0300 @@ -126,6 +126,14 @@ error = -ENOTTY; if (S_ISREG(filp->f_dentry->d_inode->i_mode)) error = file_ioctl(filp, cmd, arg); + else if (filp->f_op && filp->f_op->ioctl && + (filp->f_op->fops_flags & FOPS_IOCTL_NOLOCK)) { + { + unlock_kernel(); + error = filp->f_op->ioctl(filp->f_dentry->d_inode, filp, cmd, arg); + goto out; + + } else if (filp->f_op && filp->f_op->ioctl) error = filp->f_op->ioctl(filp->f_dentry->d_inode, filp, cmd, arg); } - 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/
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