From: Douglas Gilbert Date: Fri, 9 Sep 2005 07:18:57 +0000 (+1000) Subject: [SCSI] sg: do not set VM_IO flag on mmap-ed pages X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=1c8e71d72026ed4c6ba0fdfd7eebd865f4fd1415;p=deliverable%2Flinux.git [SCSI] sg: do not set VM_IO flag on mmap-ed pages Further to the problem discussed in this post: http://marc.theaimsgroup.com/?l=linux-scsi&m=112540053711489&w=2 It seems that the sg driver does not need to set the VM_IO flag on pages that it memory maps to the user space since they are not from the IO space. Ahmed Teirelbar wants the facility and has tested this patch as I have without adverse effects. The oops protection is still important. Some users really did try and use dio transfers from the sg driver to memory mapped IO space (on a video capture card if my memory serves) during the lk 2.4 series. I'm not sure how successful it was but that will now be politely refused in lk 2.6.13+ . Changelog: - set the page flags for sg's reserved buffer mmap-ed to the user space to VM_RESERVED (rather than VM_RESERVED | VM_IO ) Signed-off-by: Douglas Gilbert Signed-off-by: James Bottomley --- diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index b1b69d738d08..9ea4765d1d12 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -61,7 +61,7 @@ static int sg_version_num = 30533; /* 2 digits for each component */ #ifdef CONFIG_SCSI_PROC_FS #include -static char *sg_version_date = "20050901"; +static char *sg_version_date = "20050908"; static int sg_proc_init(void); static void sg_proc_cleanup(void); @@ -1299,7 +1299,7 @@ sg_mmap(struct file *filp, struct vm_area_struct *vma) sg_rb_correct4mmap(rsv_schp, 1); /* do only once per fd lifetime */ sfp->mmap_called = 1; } - vma->vm_flags |= (VM_RESERVED | VM_IO); + vma->vm_flags |= VM_RESERVED; vma->vm_private_data = sfp; vma->vm_ops = &sg_mmap_vm_ops; return 0;