The patch titled
Subject: mm-fix-xip-fault-vs-truncate-race-fix
has been removed from the -mm tree. Its filename was
mm-fix-xip-fault-vs-truncate-race-fix.patch
This patch was dropped because it was folded into mm-fix-xip-fault-vs-truncate-race.patch
------------------------------------------------------
From: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Subject: mm-fix-xip-fault-vs-truncate-race-fix
switch to i_mmap_lock_read(), add comment in unmap_single_vma()
Cc: Jan Kara <jack@xxxxxxx>
Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
Cc: Matthew Wilcox <matthew.r.wilcox@xxxxxxxxx>
Cc: Andreas Dilger <andreas.dilger@xxxxxxxxx>
Cc: Boaz Harrosh <boaz@xxxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Dave Chinner <david@xxxxxxxxxxxxx>
Cc: Jan Kara <jack@xxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Cc: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx>
Cc: Theodore Ts'o <tytso@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/filemap_xip.c | 20 +++++++++++++-------
mm/memory.c | 5 +++++
2 files changed, 18 insertions(+), 7 deletions(-)
diff -puN mm/filemap_xip.c~mm-fix-xip-fault-vs-truncate-race-fix mm/filemap_xip.c
--- a/mm/filemap_xip.c~mm-fix-xip-fault-vs-truncate-race-fix
+++ a/mm/filemap_xip.c
@@ -256,17 +256,20 @@ again:
__xip_unmap(mapping, vmf->pgoff);
found:
- /* We must recheck i_size under i_mmap_mutex */
- mutex_lock(&mapping->i_mmap_mutex);
+ /*
+ * We must recheck i_size under i_mmap_rwsem to prevent races
+ * with truncation
+ */
+ i_mmap_lock_read(mapping);
size = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
PAGE_CACHE_SHIFT;
if (unlikely(vmf->pgoff >= size)) {
- mutex_unlock(&mapping->i_mmap_mutex);
+ i_mmap_unlock_read(mapping);
return VM_FAULT_SIGBUS;
}
err = vm_insert_mixed(vma, (unsigned long)vmf->virtual_address,
xip_pfn);
- mutex_unlock(&mapping->i_mmap_mutex);
+ i_mmap_unlock_read(mapping);
if (err == -ENOMEM)
return VM_FAULT_OOM;
/*
@@ -291,8 +294,11 @@ found:
if (error != -ENODATA)
goto out;
- /* We must recheck i_size under i_mmap_mutex */
- mutex_lock(&mapping->i_mmap_mutex);
+ /*
+ * We must recheck i_size under i_mmap_rwsem to prevent races
+ * with truncation
+ */
+ i_mmap_lock_read(mapping);
size = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
PAGE_CACHE_SHIFT;
if (unlikely(vmf->pgoff >= size)) {
@@ -310,7 +316,7 @@ found:
ret = VM_FAULT_NOPAGE;
unlock:
- mutex_unlock(&mapping->i_mmap_mutex);
+ i_mmap_unlock_read(mapping);
out:
write_seqcount_end(&xip_sparse_seq);
mutex_unlock(&xip_sparse_mutex);
diff -puN mm/memory.c~mm-fix-xip-fault-vs-truncate-race-fix mm/memory.c
--- a/mm/memory.c~mm-fix-xip-fault-vs-truncate-race-fix
+++ a/mm/memory.c
@@ -1303,6 +1303,11 @@ static void unmap_single_vma(struct mmu_
* safe to do nothing in this case.
*/
if (vma->vm_file) {
+ /*
+ * Note that DAX uses i_mmap_lock to serialise
+ * against file truncate - truncate calls into
+ * unmap_single_vma().
+ */
i_mmap_lock_write(vma->vm_file->f_mapping);
__unmap_hugepage_range_final(tlb, vma, start, end, NULL);
i_mmap_unlock_write(vma->vm_file->f_mapping);
_
Patches currently in -mm which might be from akpm@xxxxxxxxxxxxxxxxxxxx are
origin.patch
mm-fix-xip-fault-vs-truncate-race.patch
mm-fix-xip-fault-vs-truncate-race-fix-fix.patch
mm-allow-page-fault-handlers-to-perform-the-cow-fix.patch
mm-allow-page-fault-handlers-to-perform-the-cow-fix-fix-3.patch
mm-allow-page-fault-handlers-to-perform-the-cow-fix-fix.patch
daxext2-replace-the-xip-page-fault-handler-with-the-dax-page-fault-handler-fix.patch
daxext2-replace-the-xip-page-fault-handler-with-the-dax-page-fault-handler-fix-2.patch
daxext2-replace-the-xip-page-fault-handler-with-the-dax-page-fault-handler-fix-3.patch
dax-add-dax_zero_page_range-fix.patch
ext4-add-dax-functionality-fix.patch
ocfs2-add-functions-to-add-and-remove-inode-in-orphan-dir-fix.patch
ocfs2-implement-ocfs2_direct_io_write-fix.patch
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