From db0badc58e948b810c7a75cfcc48845e2949ee37 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Mon, 18 Aug 2008 13:40:18 +0200 Subject: udf: Fix lock inversion between iprune_mutex and alloc_mutex (v2) A memory allocation inside alloc_mutex must not recurse back into the filesystem itself because that leads to lock inversion between iprune_mutex and alloc_mutex (and thus to deadlocks - see traces below). alloc_mutex is actually needed only to update allocation statistics in the superblock so we can drop it before we start allocating memory for the inode. tar D ffff81015b9c8c90 0 6614 6612 ffff8100d5a21a20 0000000000000086 0000000000000000 00000000ffff0000 ffff81015b9c8c90 ffff81015b8f0cd0 ffff81015b9c8ee0 0000000000000000 0000000000000003 0000000000000000 0000000000000000 0000000000000000 Call Trace: [] __mutex_lock_slowpath+0x64/0x9b [] mutex_lock+0xa/0xb [] shrink_icache_memory+0x38/0x200 [] shrink_slab+0xe3/0x15b [] try_to_free_pages+0x221/0x30d [] isolate_pages_global+0x0/0x31 [] __alloc_pages_internal+0x252/0x3ab [] cache_alloc_refill+0x22e/0x47b [] kmem_cache_alloc+0x3b/0x61 [] cache_alloc_refill+0x2fe/0x47b [] __kmalloc+0x76/0x9c [] :udf:udf_new_inode+0x202/0x2e2 [] :udf:udf_create+0x2f/0x16d [] :udf:udf_lookup+0xa6/0xad ... kswapd0 D ffff81015b9d9270 0 125 2 ffff81015b903c28 0000000000000046 ffffffff8028cbb0 00000000fffffffb ffff81015b9d9270 ffff81015b8f0cd0 ffff81015b9d94c0 000000000271b490 ffffe2000271b458 ffffe2000271b420 ffffe20002728dc8 ffffe20002728d90 Call Trace: [] __set_page_dirty+0xeb/0xf5 [] get_dirty_limits+0x1d/0x22f [] __mutex_lock_slowpath+0x64/0x9b [] mutex_lock+0xa/0xb [] :udf:udf_bitmap_free_blocks+0x47/0x1eb [] :udf:udf_discard_prealloc+0xc6/0x172 [] :udf:udf_clear_inode+0x1e/0x48 [] clear_inode+0x6d/0xc4 [] dispose_list+0x56/0xee [] shrink_icache_memory+0x1d0/0x200 [] shrink_slab+0xe3/0x15b [] kswapd+0x346/0x447 ... Reported-by: Tibor Tajti Reviewed-by: Ingo Oeser Signed-off-by: Jan Kara --- fs/udf/ialloc.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/fs/udf/ialloc.c b/fs/udf/ialloc.c index eb9cfa23dc3..c4943c8988c 100644 --- a/fs/udf/ialloc.c +++ b/fs/udf/ialloc.c @@ -111,6 +111,7 @@ struct inode *udf_new_inode(struct inode *dir, int mode, int *err) lvhd->uniqueID = cpu_to_le64(uniqueID); mark_buffer_dirty(sbi->s_lvid_bh); } + mutex_unlock(&sbi->s_alloc_mutex); inode->i_mode = mode; inode->i_uid = current->fsuid; if (dir->i_mode & S_ISGID) { @@ -145,7 +146,6 @@ struct inode *udf_new_inode(struct inode *dir, int mode, int *err) if (!iinfo->i_ext.i_data) { iput(inode); *err = -ENOMEM; - mutex_unlock(&sbi->s_alloc_mutex); return NULL; } if (UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_USE_AD_IN_ICB)) @@ -158,7 +158,6 @@ struct inode *udf_new_inode(struct inode *dir, int mode, int *err) iinfo->i_crtime = current_fs_time(inode->i_sb); insert_inode_hash(inode); mark_inode_dirty(inode); - mutex_unlock(&sbi->s_alloc_mutex); if (DQUOT_ALLOC_INODE(inode)) { DQUOT_DROP(inode); -- cgit v1.2.3-18-g5258