linux/fs/ext4
Theodore Ts'o fab3a549e2 ext4: Fix potential fiemap deadlock (mmap_sem vs. i_data_sem)
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>
2009-12-09 21:30:02 -05:00
..
acl.c ext[234]: move over to 'check_acl' permission model 2009-09-08 11:09:04 -07:00
acl.h ext[234]: move over to 'check_acl' permission model 2009-09-08 11:09:04 -07:00
balloc.c ext4: fold ext4_free_blocks() and ext4_mb_free_blocks() 2009-11-22 07:44:56 -05:00
bitmap.c ext4: Change unsigned long to unsigned int 2008-11-05 00:14:04 -05:00
block_validity.c ext4: add check for wraparound in ext4_data_block_valid() 2009-11-22 20:48:34 -05:00
dir.c ext4: Define a new set of flags for ext4_get_blocks() 2009-05-14 00:58:52 -04:00
ext4_extents.h ext4: Split uninitialized extents for direct I/O 2009-09-28 15:49:08 -04:00
ext4_jbd2.c ext4: fold ext4_journal_forget() into ext4_forget() 2009-11-22 21:00:13 -05:00
ext4_jbd2.h ext4: Wait for proper transaction commit on fsync 2009-12-08 23:51:10 -05:00
ext4.h ext4: Wait for proper transaction commit on fsync 2009-12-08 23:51:10 -05:00
extents.c ext4: Fix potential fiemap deadlock (mmap_sem vs. i_data_sem) 2009-12-09 21:30:02 -05:00
file.c const: mark struct vm_struct_operations 2009-09-27 11:39:25 -07:00
fsync.c ext4: Wait for proper transaction commit on fsync 2009-12-08 23:51:10 -05:00
hash.c ext4: Add support for non-native signed/unsigned htree hash algorithms 2008-10-28 13:21:44 -04:00
ialloc.c ext4: fix build warning when EXT4FS_DEBUG is on 2009-07-27 21:44:40 -04:00
inode.c ext4: Wait for proper transaction commit on fsync 2009-12-08 23:51:10 -05:00
ioctl.c ext4: Fix insufficient checks in EXT4_IOC_MOVE_EXT 2009-12-06 23:38:31 -05:00
Kconfig ext4: Do not override ext2 or ext3 if built they are built as modules 2009-12-09 21:09:58 -05:00
Makefile ext4: online defrag -- Add EXT4_IOC_MOVE_EXT ioctl 2009-06-17 19:24:03 -04:00
mballoc.c ext4: remove blocks from inode prealloc list on failure 2009-12-08 22:18:25 -05:00
mballoc.h ext4: Use tracepoints for mb_history trace file 2009-09-30 00:32:42 -04:00
migrate.c ext4: quota macros cleanup 2009-12-08 22:42:15 -05:00
move_extent.c ext4: Fix insufficient checks in EXT4_IOC_MOVE_EXT 2009-12-06 23:38:31 -05:00
namei.c ext4: quota macros cleanup 2009-12-08 22:42:15 -05:00
resize.c ext4: Return the PTR_ERR of the correct pointer in setup_new_group_blocks() 2009-12-07 10:38:16 -05:00
super.c ext4: Do not override ext2 or ext3 if built they are built as modules 2009-12-09 21:09:58 -05:00
symlink.c ext4: Rename ext4dev to ext4 2008-10-10 20:02:48 -04:00
xattr_security.c ext4: move headers out of include/linux 2008-04-29 18:13:32 -04:00
xattr_trusted.c ext4: remove double definitions of xattr macros 2008-07-11 19:27:31 -04:00
xattr_user.c ext4: remove double definitions of xattr macros 2008-07-11 19:27:31 -04:00
xattr.c ext4: call ext4_forget() from ext4_free_blocks() 2009-11-23 07:17:05 -05:00
xattr.h ext4: Rename ext4dev to ext4 2008-10-10 20:02:48 -04:00