diff options
| author | Davidlohr Bueso <dave@stgolabs.net> | 2014-12-12 16:54:33 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-12-13 12:42:45 -0800 |
| commit | 874bfcaf79e39135cd31e1cfc9265cf5222d1ec3 (patch) | |
| tree | 5a1406cdca818914446b73213f417e63531397d6 | |
| parent | 4a23717a236b2ab31efb1651f586126789fc997f (diff) | |
mm/xip: share the i_mmap_rwsem
__xip_unmap() will remove the xip sparse page from the cache and take down
pte mapping, without altering the interval tree, thus share the
i_mmap_rwsem when searching for the ptes to unmap.
Additionally, tidy up the function a bit and make variables only local to
the interval tree walk loop.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Acked-by: "Kirill A. Shutemov" <kirill@shutemov.name>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | mm/filemap_xip.c | 23 |
1 files changed, 9 insertions, 14 deletions
diff --git a/mm/filemap_xip.c b/mm/filemap_xip.c index bad746bde4a2..0d105aeff82f 100644 --- a/mm/filemap_xip.c +++ b/mm/filemap_xip.c @@ -155,22 +155,14 @@ xip_file_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos) EXPORT_SYMBOL_GPL(xip_file_read); /* - * __xip_unmap is invoked from xip_unmap and - * xip_write + * __xip_unmap is invoked from xip_unmap and xip_write * * This function walks all vmas of the address_space and unmaps the * __xip_sparse_page when found at pgoff. */ -static void -__xip_unmap (struct address_space * mapping, - unsigned long pgoff) +static void __xip_unmap(struct address_space * mapping, unsigned long pgoff) { struct vm_area_struct *vma; - struct mm_struct *mm; - unsigned long address; - pte_t *pte; - pte_t pteval; - spinlock_t *ptl; struct page *page; unsigned count; int locked = 0; @@ -182,11 +174,14 @@ __xip_unmap (struct address_space * mapping, return; retry: - i_mmap_lock_write(mapping); + i_mmap_lock_read(mapping); vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) { - mm = vma->vm_mm; - address = vma->vm_start + + pte_t *pte, pteval; + spinlock_t *ptl; + struct mm_struct *mm = vma->vm_mm; + unsigned long address = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT); + BUG_ON(address < vma->vm_start || address >= vma->vm_end); pte = page_check_address(page, mm, address, &ptl, 1); if (pte) { @@ -202,7 +197,7 @@ retry: page_cache_release(page); } } - i_mmap_unlock_write(mapping); + i_mmap_unlock_read(mapping); if (locked) { mutex_unlock(&xip_sparse_mutex); |