another .31 patch

diff --git a/queue-2.6.31/ext4-fix-potential-fiemap-deadlock-mmap_sem-vs.-i_data_sem.patch b/queue-2.6.31/ext4-fix-potential-fiemap-deadlock-mmap_sem-vs.-i_data_sem.patch
new file mode 100644 (file)
index 0000000..323663d
--- /dev/null
+++ b/queue-2.6.31/ext4-fix-potential-fiemap-deadlock-mmap_sem-vs.-i_data_sem.patch
@@ -0,0 +1,122 @@
+From stable-bounces@linux.kernel.org Thu Dec 10 15:52:55 2009
+From: "Theodore Ts'o" <tytso@mit.edu>
+Date: Thu, 10 Dec 2009 18:51:31 -0500
+Subject: ext4: Fix potential fiemap deadlock (mmap_sem vs. i_data_sem)
+To: stable@kernel.org
+Cc: "Theodore Ts'o" <tytso@mit.edu>
+Message-ID: <1260489091-29892-1-git-send-email-tytso@mit.edu>
+
+(cherry picked from commit fab3a549e204172236779f502eccb4f9bf0dc87d)
+
+Fix the following potential circular locking dependency between
+mm->mmap_sem and ei->i_data_sem:
+
+    =======================================================
+    [ INFO: possible circular locking dependency detected ]
+    2.6.32-04115-gec044c5 #37
+    -------------------------------------------------------
+    ureadahead/1855 is trying to acquire lock:
+     (&mm->mmap_sem){++++++}, at: [<ffffffff81107224>] might_fault+0x5c/0xac
+
+    but task is already holding lock:
+     (&ei->i_data_sem){++++..}, at: [<ffffffff811be1fd>] ext4_fiemap+0x11b/0x159
+
+    which lock already depends on the new lock.
+
+    the existing dependency chain (in reverse order) is:
+
+    -> #1 (&ei->i_data_sem){++++..}:
+           [<ffffffff81099bfa>] __lock_acquire+0xb67/0xd0f
+           [<ffffffff81099e7e>] lock_acquire+0xdc/0x102
+           [<ffffffff81516633>] down_read+0x51/0x84
+           [<ffffffff811a2414>] ext4_get_blocks+0x50/0x2a5
+           [<ffffffff811a3453>] ext4_get_block+0xab/0xef
+           [<ffffffff81154f39>] do_mpage_readpage+0x198/0x48d
+           [<ffffffff81155360>] mpage_readpages+0xd0/0x114
+           [<ffffffff811a104b>] ext4_readpages+0x1d/0x1f
+           [<ffffffff810f8644>] __do_page_cache_readahead+0x12f/0x1bc
+           [<ffffffff810f86f2>] ra_submit+0x21/0x25
+           [<ffffffff810f0cfd>] filemap_fault+0x19f/0x32c
+           [<ffffffff81107b97>] __do_fault+0x55/0x3a2
+           [<ffffffff81109db0>] handle_mm_fault+0x327/0x734
+           [<ffffffff8151aaa9>] do_page_fault+0x292/0x2aa
+           [<ffffffff81518205>] page_fault+0x25/0x30
+           [<ffffffff812a34d8>] clear_user+0x38/0x3c
+           [<ffffffff81167e16>] padzero+0x20/0x31
+           [<ffffffff81168b47>] load_elf_binary+0x8bc/0x17ed
+           [<ffffffff81130e95>] search_binary_handler+0xc2/0x259
+           [<ffffffff81166d64>] load_script+0x1b8/0x1cc
+           [<ffffffff81130e95>] search_binary_handler+0xc2/0x259
+           [<ffffffff8113255f>] do_execve+0x1ce/0x2cf
+           [<ffffffff81027494>] sys_execve+0x43/0x5a
+           [<ffffffff8102918a>] stub_execve+0x6a/0xc0
+
+    -> #0 (&mm->mmap_sem){++++++}:
+           [<ffffffff81099aa4>] __lock_acquire+0xa11/0xd0f
+           [<ffffffff81099e7e>] lock_acquire+0xdc/0x102
+           [<ffffffff81107251>] might_fault+0x89/0xac
+           [<ffffffff81139382>] fiemap_fill_next_extent+0x95/0xda
+           [<ffffffff811bcb43>] ext4_ext_fiemap_cb+0x138/0x157
+           [<ffffffff811be069>] ext4_ext_walk_space+0x178/0x1f1
+           [<ffffffff811be21e>] ext4_fiemap+0x13c/0x159
+           [<ffffffff811390e6>] do_vfs_ioctl+0x348/0x4d6
+           [<ffffffff811392ca>] sys_ioctl+0x56/0x79
+           [<ffffffff81028cb2>] system_call_fastpath+0x16/0x1b
+
+    other info that might help us debug this:
+
+    1 lock held by ureadahead/1855:
+     #0:  (&ei->i_data_sem){++++..}, at: [<ffffffff811be1fd>] ext4_fiemap+0x11b/0x159
+
+    stack backtrace:
+    Pid: 1855, comm: ureadahead Not tainted 2.6.32-04115-gec044c5 #37
+    Call Trace:
+     [<ffffffff81098c70>] print_circular_bug+0xa8/0xb7
+     [<ffffffff81099aa4>] __lock_acquire+0xa11/0xd0f
+     [<ffffffff8102f229>] ? sched_clock+0x9/0xd
+     [<ffffffff81099e7e>] lock_acquire+0xdc/0x102
+     [<ffffffff81107224>] ? might_fault+0x5c/0xac
+     [<ffffffff81107251>] might_fault+0x89/0xac
+     [<ffffffff81107224>] ? might_fault+0x5c/0xac
+     [<ffffffff81124b44>] ? __kmalloc+0x13b/0x18c
+     [<ffffffff81139382>] fiemap_fill_next_extent+0x95/0xda
+     [<ffffffff811bcb43>] ext4_ext_fiemap_cb+0x138/0x157
+     [<ffffffff811bca0b>] ? ext4_ext_fiemap_cb+0x0/0x157
+     [<ffffffff811be069>] ext4_ext_walk_space+0x178/0x1f1
+     [<ffffffff811be21e>] ext4_fiemap+0x13c/0x159
+     [<ffffffff81107224>] ? might_fault+0x5c/0xac
+     [<ffffffff811390e6>] do_vfs_ioctl+0x348/0x4d6
+     [<ffffffff8129f6d0>] ? __up_read+0x8d/0x95
+     [<ffffffff81517fb5>] ? retint_swapgs+0x13/0x1b
+     [<ffffffff811392ca>] sys_ioctl+0x56/0x79
+     [<ffffffff81028cb2>] system_call_fastpath+0x16/0x1b
+
+Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
+Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
+---
+ fs/ext4/extents.c |    4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+--- a/fs/ext4/extents.c
++++ b/fs/ext4/extents.c
+@@ -1742,7 +1742,9 @@ int ext4_ext_walk_space(struct inode *in
+       while (block < last && block != EXT_MAX_BLOCK) {
+               num = last - block;
+               /* find extent for this block */
++              down_read(&EXT4_I(inode)->i_data_sem);
+               path = ext4_ext_find_extent(inode, block, path);
++              up_read(&EXT4_I(inode)->i_data_sem);
+               if (IS_ERR(path)) {
+                       err = PTR_ERR(path);
+                       path = NULL;
+@@ -3707,10 +3709,8 @@ int ext4_fiemap(struct inode *inode, str
+                * Walk the extent tree gathering extent information.
+                * ext4_ext_fiemap_cb will push extents back to user.
+                */
+-              down_read(&EXT4_I(inode)->i_data_sem);
+               error = ext4_ext_walk_space(inode, start_blk, len_blks,
+                                         ext4_ext_fiemap_cb, fieinfo);
+-              up_read(&EXT4_I(inode)->i_data_sem);
+       }
+ 
+       return error;

diff --git a/queue-2.6.31/series b/queue-2.6.31/series
index 19216e40afb9eae4750a5a65b435fab3d61c1816..f9e4c5b173f0794e55f326c42953d5a64078327b 100644 (file)
--- a/queue-2.6.31/series
+++ b/queue-2.6.31/series
@@ -87,3 +87,4 @@ scsi-megaraid_sas-fix-64-bit-sense-pointer-truncation.patch
 scsi-osd_protocol.h-add-missing-include.patch
 scsi-scsi_lib_dma-fix-bug-with-dma-maps-on-nested-scsi-objects.patch
 signal-fix-alternate-signal-stack-check.patch
+ext4-fix-potential-fiemap-deadlock-mmap_sem-vs.-i_data_sem.patch