From 55bd725aa3a83b3935988f37275b5a80e10d4169 Mon Sep 17 00:00:00 2001 From: "Aneesh Kumar K.V" Date: Fri, 15 Feb 2008 12:47:21 -0500 Subject: [PATCH] ext4: Fix locking hierarchy violation in ext4_fallocate() ext4_fallocate() was trying to acquire i_data_sem outside of jbd2_start_transaction/jbd2_journal_stop, which violates ext4's locking hierarchy. So we take i_mutex to prevent writes and truncates during the complete fallocate operation, and use ext4_get_block_wrap() which acquires and releases i_data_sem for each block allocation. Signed-off-by: Aneesh Kumar K.V Signed-off-by: Mingming Cao Signed-off-by: "Theodore Ts'o" --- fs/ext4/extents.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index bc7081f..e856f66 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -2623,7 +2623,7 @@ long ext4_fallocate(struct inode *inode, int mode, loff_t offset, loff_t len) * modify 1 super block, 1 block bitmap and 1 group descriptor. */ credits = EXT4_DATA_TRANS_BLOCKS(inode->i_sb) + 3; - down_write((&EXT4_I(inode)->i_data_sem)); + mutex_lock(&inode->i_mutex); retry: while (ret >= 0 && ret < max_blocks) { block = block + ret; @@ -2634,7 +2634,7 @@ retry: break; } - ret = ext4_ext_get_blocks(handle, inode, block, + ret = ext4_get_blocks_wrap(handle, inode, block, max_blocks, &map_bh, EXT4_CREATE_UNINITIALIZED_EXT, 0); WARN_ON(ret <= 0); @@ -2680,7 +2680,6 @@ retry: if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries)) goto retry; - up_write((&EXT4_I(inode)->i_data_sem)); /* * Time to update the file size. * Update only when preallocation was requested beyond the file size. @@ -2692,21 +2691,18 @@ retry: * if no error, we assume preallocation succeeded * completely */ - mutex_lock(&inode->i_mutex); i_size_write(inode, offset + len); EXT4_I(inode)->i_disksize = i_size_read(inode); - mutex_unlock(&inode->i_mutex); } else if (ret < 0 && nblocks) { /* Handle partial allocation scenario */ loff_t newsize; - mutex_lock(&inode->i_mutex); newsize = (nblocks << blkbits) + i_size_read(inode); i_size_write(inode, EXT4_BLOCK_ALIGN(newsize, blkbits)); EXT4_I(inode)->i_disksize = i_size_read(inode); - mutex_unlock(&inode->i_mutex); } } + mutex_unlock(&inode->i_mutex); return ret > 0 ? ret2 : ret; } -- 2.7.4