From: Paolo 'Blaisorblade' Giarrusso <[EMAIL PROTECTED]>
Assume that even after dropping and reacquiring the lock, (vma->vm_flags &
VM_SHARED) won't change, thus moving a check earlier.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <[EMAIL PROTECTED]>
---
linux-2.6.git-paolo/mm/fremap.c | 12 ++----------
1 files changed, 2 insertions(+), 10 deletions(-)
diff -puN mm/fremap.c~rfp-assume-VM_PRIVATE-stays mm/fremap.c
--- linux-2.6.git/mm/fremap.c~rfp-assume-VM_PRIVATE-stays 2005-08-11
12:58:07.000000000 +0200
+++ linux-2.6.git-paolo/mm/fremap.c 2005-08-11 13:38:56.000000000 +0200
@@ -232,6 +232,8 @@ retry:
/* Must set VM_NONLINEAR before any pages are populated. */
if (pgoff != linear_page_index(vma, start)) {
+ if (!(vma->vm_flags & VM_SHARED))
+ goto out_unlock;
if (!(vma->vm_flags & VM_NONLINEAR)) {
if (!has_write_lock) {
up_read(&mm->mmap_sem);
@@ -239,12 +241,6 @@ retry:
has_write_lock = 1;
goto retry;
}
- /* XXX: we check VM_SHARED after re-getting the
- * (write) semaphore but I guess that we could
- * check it earlier as we're not allowed to turn
- * a VM_PRIVATE vma into a VM_SHARED one! */
- if (!(vma->vm_flags & VM_SHARED))
- goto out_unlock;
mapping = vma->vm_file->f_mapping;
spin_lock(&mapping->i_mmap_lock);
@@ -254,10 +250,6 @@ retry:
vma_nonlinear_insert(vma,
&mapping->i_mmap_nonlinear);
flush_dcache_mmap_unlock(mapping);
spin_unlock(&mapping->i_mmap_lock);
- } else {
- /* Won't drop the lock, check it here.*/
- if (!(vma->vm_flags & VM_SHARED))
- goto out_unlock;
}
}
_
-
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