The patch titled
mm: tiny-shmem fix lock ordering: mmap_sem vs i_mutex
has been added to the -mm tree. Its filename is
mm-tiny-shmem-fix-lor-mmap_sem-vs-i_mutex.patch
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------------------------------------------------------
Subject: mm: tiny-shmem fix lock ordering: mmap_sem vs i_mutex
From: Nick Piggin <npiggin@xxxxxxx>
tiny-shmem calls do_truncate in shmem_file_setup. do_truncate takes
i_mutex, and shmem_file_setup is called with mmap_sem held. However
i_mutex nests outside mmap_sem.
Copy the code in shmem.c to avoid this problem.
Signed-off-by: Nick Piggin <npiggin@xxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Matt Mackall <mpm@xxxxxxxxxxx>
Cc: Hugh Dickins <hugh@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/tiny-shmem.c | 26 ++++++++++----------------
1 file changed, 10 insertions(+), 16 deletions(-)
diff -puN mm/tiny-shmem.c~mm-tiny-shmem-fix-lor-mmap_sem-vs-i_mutex mm/tiny-shmem.c
--- a/mm/tiny-shmem.c~mm-tiny-shmem-fix-lor-mmap_sem-vs-i_mutex
+++ a/mm/tiny-shmem.c
@@ -65,31 +65,25 @@ struct file *shmem_file_setup(char *name
if (!dentry)
goto put_memory;
+ error = -ENFILE;
+ file = get_empty_filp();
+ if (!file)
+ goto put_dentry;
+
error = -ENOSPC;
inode = ramfs_get_inode(root->d_sb, S_IFREG | S_IRWXUGO, 0);
if (!inode)
- goto put_dentry;
-
- d_instantiate(dentry, inode);
- error = -ENFILE;
- file = alloc_file(shm_mnt, dentry, FMODE_WRITE | FMODE_READ,
- &ramfs_file_operations);
- if (!file)
- goto put_dentry;
-
- inode->i_nlink = 0; /* It is unlinked */
-
- /* notify everyone as to the change of file size */
- error = do_truncate(dentry, size, 0, file);
- if (error < 0)
goto close_file;
+ d_instantiate(dentry, inode);
+ inode->i_size = size;
+ inode->i_nlink = 0; /* It is unlinked */
+ init_file(file, shm_mnt, dentry, FMODE_WRITE | FMODE_READ,
+ &ramfs_file_operations);
return file;
close_file:
put_filp(file);
- return ERR_PTR(error);
-
put_dentry:
dput(dentry);
put_memory:
_
Patches currently in -mm which might be from npiggin@xxxxxxx are
linux-next.patch
sysfs-fix-deadlock.patch
inotify-fix-lock-ordering-wrt-do_page_faults-mmap_sem.patch
mm-tiny-shmem-fix-lor-mmap_sem-vs-i_mutex.patch
vmscan-move-isolate_lru_page-to-vmscanc.patch
mlock-mlocked-pages-are-unevictable.patch
mlock-mlocked-pages-are-unevictable-fix.patch
mmap-handle-mlocked-pages-during-map-remap-unmap.patch
vmstat-mlocked-pages-statistics.patch
mm-pagecache-insertion-fewer-atomics.patch
mm-unlockless-reclaim.patch
mm-page-lock-use-lock-bitops.patch
fs-buffer-lock-use-lock-bitops.patch
mm-page-allocator-minor-speedup.patch
mm-rewrite-vmap-layer.patch
mm-rewrite-vmap-layer-fix.patch
mm-rewrite-vmap-layer-fix-fix.patch
mm-rewrite-vmap-layer-fix-fix-fix.patch
reiser4.patch
likeliness-accounting-change-and-cleanup.patch
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